GENERAL QUESTIONS ON SCIENCE & TECHNOLOGY
( BASED ON BOOKS PRESCRIBED IN SCHOOLS FOR PHYSICAL
SCIENCE)
PHYSICS
OUR UNIVERSE
– GRAVITATION:
1) Copernican theory is also known as
_____________________________
Ans
: Helio centric theory
2) Mass (M) of earth is
_________
Ans:
6 x 1024 Kg
3) Radius of earth is ______________
Ans: 6.4 x 106 m
4) the value of ‘g’ on the earth in S.I. system is
_____________
Ans
: 9.8 m/s2
5) The value of ‘g’ on the moon is ____________
Ans
: 1.67 m/s 2
6) the value of ‘g’ on the sun is ______________
Ans
: 27.4 m/s2
7) The force that keeps the planets in their orbits is
the _______ of the sun
Ans
: gravitational force
8) The moon makes one revolution about the earth in
______ days
Ans
: 27.3
9) The distance of the moon from the earth is about
___________ KMs
Ans:
3.85 x 105
10) The basis of Newton’s Laws of universal gravitation
is ___________
Ans
: Kepler’s Laws
11) Orbiting around the sun in circular orbits is first
proposed by _______
Ans
: Copernicus
12) The path of a planet around the sun is ________
Ans
: elliptical
13) The value of ‘g’ at the poles of the earth is _______
Ans
: maximum
14) The value of ‘g’ at the equator is __________
Ans
: minimum
15) 1 Kilogram weight on earth is equal to _________
Ans
: 9.8 Newtons
16) The orbital velocity required for an object to go
round the earth is _______
Ans
: around 8 km/sec
17) Escape velocity of an object, to go out of the gravitational
pull of the earth is _____
Ans
: 11.2 Km/sec
18) Ecape velocity of an object, to go out of the
gravitational pull of the sun is ________
Ans
: about 42 KM/sec
19) Mass of a body anywhere in the world is __________
Ans
: same
DYNAMICS:
1) Circular
motion is a special case of ______
Ans : rotator motion
2) If the string
of whirling stone is cut, the stone moves in ___________
Ans: tangential
3) In a uniform
circular motion the angular velocity is __________
Ans : constant
4) Centre seeking
force is called as ______________
Ans : Centripetal force
5) Centrifugal
force means __________
Ans : centre fleeing force or a
force directed away from the centre
6) Newton’s laws
are valid in _______ frame of reference.
Ans : inertial
7) The study of
motion of a body under the action of force is called __________
Ans : dynamics
8) Examples for
translator motion ______________
Ans (1) motionof a flywheel,(2) motion of earth about its axis
9) Examples for
oscillatory motion ______________
Ans : (1) motion of a pendulum
(2) motion of mass attached to a
string
10) Earth goes
round the sun because of _______ of attraction between them.
Ans : gravitational force
11) The
gravitational force of attraction provides the necessary ______ for a satellite
revolving round a planet.
Ans : centripetal force
12) When electron
revolves round the nucleus in an atom, the centripetal force is provided by the
_________ of attraction between them.
Ans : electro static force
13) Centrifugal
force is also known as ____________
Ans : fictitious force or pseudo
force
14) A _______________ is used to separate
particles of higher mass from the lower mass in a given mixture.
Ans : centrifuge
15) When a
running car takes a sudden left turn, a man sitting in the back seat falls to
the right due to _______ of direction.
Ans : inertia
16) The magnitude
of centripetal force and centrifugal force is ______
Ans: same
17) ________
depends on the expected speed of vehicle and the radius of the curvature of the
road.
Ans: Banking angle
18) _______ is a
body orbiting around another body.
Ans : Satellite
19) Earth goes
round the sun because of ________
Ans : gravitational force of
attraction
20) The
domestic churner works on the principle
of a __________
Ans : centrifuge
21) The natural
satellite of earth is ________
Ans : Moon
22) Satellites
and space stations used for study of planets, stars and _____ in the universe.
Ans : galaxies
23) “The orbinal
velocity of an artificial satellite is ________ km/sec.
Ans : about 8 and less than 11
24) ____________
force is a pull on the body towards the centre of a circle.
Ans : Centripetal
25) The principle
of launching an artificial satellite into orbit is to sufficient intial _____
speed such that it revolves round the earth at the choosen height.
Ans : horizontal
26) The device
used to separate particles of higher mass from those of lower mass in a given
mixture _______
Ans : centrifuge
27) A car moves
on a curved but level road. The
necessary centripetal force on the car is provided by ___________
Ans : friction between the tyres
and the road
SIMPLE HARMONIC
MOTION :
1) Any motion
that repeats itself along the same path in equal intervals of time is called a
_________
Ans : periodic motion
2) Periodic
motion is also called as _______
Ans : harmonic motion
3) A
_____________ is associated with every wave motion.
Ans : simple harmonic motion
4) The time
period of a simple pendulum is ____________
Ans : directly proportional to
the square root of length
ELECTROMAGNETIC
SPECTRUM :
1)What is
Spectrum ?
Ans
: Spectrum is a group of wave lengths or frequencies.
2) When a ray of sun light falls on a prism, the
transmitted light produces a sequence of colours called a _________
Ans : visible spectrum or
VIBGYOR
3) The prisms
made of ______ are used to defect Infra red radiations.
Ans : rock salt
4) The invisible
radiation before violet are called _______
Ultraviolet radiations
5) __________
radiations are characterized by oscillating electric and magnetic fields
perpendicular to each other and perpendicular to the direction of propagation.
Ans : electromagnetic
6) The waves
travelling with velocity of light and consisting of Oscillating electric and
magnetic fields perpendicular to each other and also perpendicular to the
direction of their propagation form the __________
Ans : electromagnetic spectrum
7) The wavelength
of the Visible spectrum extends from about 0.4 µ m to _______ that is from
violet to red colour.
Ans : 0.7 µ m
8)
_______________ spectrum is emitted when the excited valence electrons in atoms
jump to their normal states.
Ans : Visible
9) _____________
radiations are emitted by atoms or molecules when they change their states of
rotational to vibrational motion.
Ans : Infra red
10) _______
radiations can be detected by thermopile
Ans : Infra red
11) Infra red
radiations find applications in _________
Ans : physiotherapy
12) Infra red
radiations are also used to take photographs of objects in ________
Ans : darkness
13) The wave
length of the micro waves are in the range from _________ to ________
Ans: 10 µ m to 1 n m
14) Radio waves
have wavelengths from _______ to about
_________
Ans : 1 m ,
100 KM
15) Radio waves
are produced by the electromagnetic oscillators of __________
Ans : low frequency
16) _________
radiations are produced by the high energy transitions of the electrons in
atoms
Ans : Ultra violet
17) We are protected
from ultraviolet radiations of the sun due to _____ layer in our atmosphere.
Ans: ozone
18) Wave lengths
of x-rays range from ______ to ______
Ans : 0.001 nm,
10nm or 0.01 Ã… m 100 Ã…
19) ___________
are produced in discrete wavelengths in individual transitions amon g the inner
electrons of an atom.
Ans : X-rays
20) X-rays of
short wavelengths are also called as __________
Ans : hard x-rays
21) Soft x-rays are used in medical diagnosis called
_____________
Ans : radiography
22) x-rays are
also used to cure some diseases. This
method is called ________
Ans : radio therapy
23) gamma ( γ ) rays are emitted in __________
Ans : radio activity
24) All
electromagnetic waves are ____________ in nature .
Ans : transverse
25) The visible
spectrum is emitted when excited valence ____ in atoms jump to their normal
states.
Ans: electrons
26) The colour of
light emitted by a particular substance is characteristic of the ____ of the
substance.
Ans : atoms
27) The light
emitted from the sun and distant stars give information about the _____ of the
matter present in them.
Ans : composition
28) IR
means_______
Ans : Infra red
29) Infra red
radiations are emitted by _______ when they change their states of rotational
or vibrational motion.
Ans : molecules
30) Hot bodies
form sources of the _______ radiations
Ans : Infra red
31) IR radiations
can be detected by ___________
Ans : Thermopile or bolomometer
32) Microwaves
are produced by high frequency electromagnetic _____ in electric circuits
Ans : Oscillators
33) ___________
waves are used in satellite communications
Ans : Micro waves
34) Mapping of
the radio emissions from extra terrestrial sources is known as ________
Ans : radio radiations
35) UV means
_______
Ans : Ultra violet rays/ ultra
violet spectrum
36) RADAR means
_________
Ans : Radio detection and
ranging
37) The reason of depletion of ozone layer in
atmosphere is due to the reactions with ________
Ans: chloro fluro carbons
38) Speed of
light in vacuum is ___________
Ans : 3 x 10 8 m/sec
39) Microwaves
are often used in _________
Ans : RADAR
40) The type of
radiations used in Radar are ________
Ans : Microwaves
SOUND :
1) Speed of sound
in air is ________
Ans : 333 mps ( in normal
conditions)
2) _____________ is the phenomenon in which if
one of the two bodies of the same
natural frequency is set into vibration, the other body also vibrates with
large amplitude under the influence of the first body.
Ans : Resonance
3) ____________
is not transmitted in stationary waves.
Ans : Energy
4) Sound waves
travel in air are ___________ waves
Ans : longitudinal
5) _____________
waves are formed in a resonating air column.
Ans: Stationary
6) The periodic
vibrations of decreasing amplitude are called ______ vibrations.
Ans : damped
7) Everybody has
its own frequency called ________
Ans : natural frequency
8) Velocity of
sound is maximum in ______
Ans : solids ( like iron rods)
9) The velocity
of sound in vacuum is ________
Ans : zero
10) When the
soldiers cross a suspension bridge they are asked to break their steps to
prevent_______
Ans : resonance
11) A tuning fork
vibrates when a vibrating tuning fork is brought near it. This is due to _____
Ans : rersonance
12) Velocity of
sound on moon is _______
Ans : zero
13) The longest
wave is ________
Ans : Radio wave
14) In a
resonating air column ____ waves are formed.
Ans : stationary
LIGHT
NATURE OF LIGHT & SOURCES OF LIGHT
1) Newton
proposed ________ theory of light
Ans : corpuscles
2) Corpuscles are
_____ by the reflecting surface
Ans : repelled
3) Corpuscles are
______ by the refracting surface
Ans : attracted
4) Wave theory of
light was proposed by __________
Ans : Huygens
5) According to
Newton, the colours of light are due to
difference in the ______ of corpuscles.
Ans : different sizes
6) Light rays can
be produced from __________ body
Ans : luminous
7) Examples of
luminous bodies are _______
Ans: Sun, Stars
8) Maxwell proposed
_________ theory of light
Ans : electromagnetic
9) Light consists
of radiations called ________
Ans : photons
10) Light waves
are ________
Ans : transverse
11) In a ripple
tank , crest of the light wave, behaves as _____ lens
Ans : convex
12) In a ripple
tank the trough of light wave behaves as ______ lens
Ans : concave
13) In a ripple
tank _____ band is formed due to crests
Ans : bright
14) In a ripple
tank _____ band is formed due to troughs
Ans : dark
15) Speed of
light in vacuum is _________
Ans : 3 x 10 8 m/sec
Visual
Photometry:
1) The visual
light is an energy on the _______
Ans : flow
2) Example for
self luminous body is ________
Ans : Sun
3) Unit of
luminous flux is ________
Ans : Lumen
4) Sun light has
its maximum radiant energy close to ________
Ans: green light
LASER:
1)Laser stands for __________
Ans
: Light Amplification by Stimulated Emission of Radiation
2) The light used in destroying ICBM is in itself is __________
Ans
: Laser
3) First laser was called _________
Ans
: pulsed laser
4) The basic scientific principle behind a laser was put
forward by ________
Ans
: Dr. Charles
5) ICBM stands for _____
Ans
: Inter Continental Ballistic Missile
6) The property coherence in Laser is called ________
Ans
: temporal coherence
7) Lack of coherence makes ordinary light an ______
Ans
: optical noise
8) Coherence makes a laser light _____
Ans
: optical music
9) The important characteristic properties of laser are
________
Ans
: 1) coherence 2) directionality
3) monochromacity and high intensity
10) Example for monochromatic light is _______
Ans
: sodium lamp
11) Laser emits light only in one dirction. This is called _____ of laser light.
Ans:
directionality
12) The process of achieving population inversion is
called _________
Ans
: pumping ( It is a word used in Lasers)
13) The process of electrons being released on their own
from the excited states in atoms and emitting incoherent light is called
________
Ans
: spontaneous emission
14) _______ are used for bloodless surgery
Ans
: Lasers
15) Lasers are used now for __________
Ans
: drilling, cutting materials
16) Lasers are used in guided ______ and to deflect enemy
target
Ans
: missiles
17) Lasers employed in special 3-dimensional photography
are called _______
Ans
: Holography
18) The development of lasers which helped in
establishing a new revolutionary method of communications called __________
Ans
: fibre optic communication
19) The spread of wavelength about the maximum intensity
is called ______
Ans
: Band width
20) Ruby laser is an example for ______
Ans
: solid laser
21) Helium – Neon laser is an example for _______
Ans
: gaseous laser
22) The three dimensional photography is called _____
Ans
: Holography
23) The process of achieving “population inversion” is
called_____
Ans
: pumping
24) By ______ large energy can be concentrated into an
extremely small band width.
Ans
: Monochromacity
25) The light from an ordinary light source spreads out
uniformly in all directions and forms ______ wave fronts around it.
Ans
: spherical
PHYSICS – 3
MAGNETISM :
1) Give examples for magnetic substances?
Ans
: Iron, Nickel, Cobalt
2) Give examples for non-magnetic substances?
Ans
: Brass, Paper, Wood
3) The property of a magnetism exhibited by magnetic
substances has given into the ____ of electron in atoms
Ans
: configuration
4) The idea of magnetism was first proposed by ________
Ans
: Weber
5) Magnet attracts the iron due to _______
Ans
: Induction
6) Magnetic poles always exist in_______
Ans
: pairs
7) Two poles of a bar magnet have equal _______
Ans
: strength
8) A magnet can be demagnetized by ___________
Ans
: tapping o r hammering or heating
9) In soft iron the ailments are distributed easily.
Therefore it is used to make _____
Ans
: electromagnets
10) _______ is the unit of magnetic pole strength in
M.K.S.system
Ans
: Weber
11) The unit of an intensity of a magnetic field in
C.G.S. system is ______
Ans:
Gauss
12) One Tesla is
________
Ans
: 104 Gauss
13) When the North Pole of the bar magnet facing North
Pole of the earth, the null points are formed on _______
Ans
: equatorial line
14) Whe the south pole of the bar magnet facing North
Pole on the earth, the null points are formed on ______
Ans
: axial line
15) The line joining the two poles is ________
Ans
: magnetic axis
Magnetic Properties of Materials :
16) All materials can be classified in to ____________
magnetic materials.
Ans
: 1) dia 2) para and 3) ferro
17) Oxygen, solution of salts of nickel, manganese,
aluminium, platinum and chromium are some of the ______ substances.
Ans
: paramagnetic
18) Iron, Cobalt, Nickel, Gadolinium, Dysprosium, and
large number of their alloys are _______ substances.
Ans:
ferromagnetic
19) The property of retaining certain amount of intensity
of magnetization even after removal of applied magnetic field is called
________
Ans
: retentivity
20) ____________ substances are those in which the
resultant magnetic moment of individual atoms is zero.
Ans
: dia-magnetic
21) Manganese is an example for ____ magnetic material.
Ans : para
22) In each atom _____ revolve round the nucleus in
orbits.
Ans
: electrons
23) Electron carries _______ charge
Ans
: negative
24) The motion of the electrons cause _____ and electric
currents to appear in orbit.
Ans
: current
25) The electric current produces a _______ field
Ans
: magnetic
26) The magnetic field in the atom or molecule behaves as
a ________
Ans
: magnet
27) The magnet is said to have _______
Ans
: magnetic moment
28) The spin motion of an electron also gives rise to a
________
Ans
: magnetic behavior
29) When a substance is placed in a magnetic field, the
atomic magnets tend to align _____ to the direction of the applied field.
Ans
: parallel
30) The cause for magnetism in a steel magnet is due to
the ________
Ans
: spi of electrons
31) Iron is ferromagnetic below_______
Ans
: 770 ° C
32) An electromagnet
is made of _________
Ans
: soft iron
33) Permanent magnets are made of _______
Ans
: steel
34) The magnetism of the atom is due to _____ around
nucleus and spin of the electron.
Ans
: electrons
35) The ferromagnetic substances are strongly attracted
by a _________
Ans
: magnet
36) When paramagnetic substance is brought near a
magnetic pole of a bar magnet, it develops an opposite or unlike ______ and
therefore it is attracted by it.
Ans
: pole
37) A paramagnetic substance suspended freely in a
magnetic field is attracted towards stronger field and tends align along the
direction of the ________
Ans
: magnetic field
38) The S.I.Unit of magnetic induction is ________
Ans
: Tesla
39) Example of a para magnetic substance is ______
Ans
: Oxygen
40) The S.I.Unit of magnetic flux density is _________
Ans
: Newton/ampere – metre
41) The magnetic nature of a substance is determined by
________
Ans
: Spin of its electrons
42) One Tesla is equivalent to _________
Ans
: 10 4 gauss
43) The S.I.unit of magnetic flux is _________
Ans
: Weber
44) The magnetism of a magnet may be destroyed by
___________
Ans
: tapping, heating, hammering
45) Spontaneous magnetization exists only in __________
Ans:
Ferromagnetic substances
46) The exact test
for magnetism is _________
Ans
: Repulsion
47) Substances very strongly attracted by the magnet ,
called__________
Ans
: Ferromagnets
48) _____ is not a diamagnetic substance
Ans:
Iron
49) Air, water, bismuth, gold, alcohol, mercury and
hydrogen are some of the _____ substances.
Ans
: diamagnetic
50) The S.I.Unit of magnetic moment is _________
Ans
: Ampere – meter 2
ELECTRICITY
Simple Electric Circuits:
1) The Unit of electric current is ______
Ans
: Amperes
2) Potential difference is measured in _______
Ans
: Volts
3) The instrument used for measuring current is _______
Ans
: Ammeter
4) Tap-Key is used to make and _______ an electric
circuit.
Ans
: break
5) The study of electric charges at rest is called ________
Ans:
static electricity
6) The study of various effects of electrical charges in
motion is called _______
Ans
: Current electricity
7) The flow of
chargers in a conductor constitutes an ______ in it.
Ans
: electric current
8) The current is measured in amperes using an ______
Ans
: Ammeter
9) Free electrons are available in_________
Ans
: metals
10) Unit of power is ________
Ans
: Watt or Joule/Sec
11) When negative terminal of a cell is connected to the
positive terminal of the next cell, then the cells are said to be in
_____________
Ans
: Series
12) When all positive terminals of two or more cells are
connected to a single point and similarly all the negative terminals are
connected to another single point, then the cells are said to be connected in
_________
Ans
: Parallel
13) The P.D. of an electrical device or energy source is
called its _________
Ans
: Voltage
14) Battery or cell is the seat of _______
Ans
: e.m.f.
15) E.m.f. is nothing but work done per unit ______
chanrge.
Ans
: positive
16) E.M.f. is measured in _______
Ans
: Volts
Electrical Resistance:
1) The electrical property of a conductor which opposites
the flow of electrons through it is called ________
Ans
: Electric resistance
2) _______ are good conductors of electricity
Ans
: metals
3) The unit of resistance is _______
Ans
: Ohm
4) Metals are good ________
Ans
: conductors
5) Metallic nature is due to availability of ________
electrons
Ans
: free
6) Metals are good conductors because of free ______
Ans
: electrons
7) Resistance opposes the flow of _________
Ans:
electrons
8) In a conductor, the flow of current is flow of free
______
Ans
: electrons
9) The instrument to measure current is ________
Ans
: Ammeter
LAW OF RESISTANCE:
1) The resistance of some semiconductors like ______
changes significantly when exposed to light.
Ans
: selenium
2) Addition of _________ changes the resistance of a material.
Ans
: impurities
3) Impurities have a marked effect on the resistance of
_________
Ans
: Semiconductors
HEATING EFFECTS OF ELECTRIC CURRENT:
1) When electric current passes through a resistance,
_____ is produced.
Ans
: heat
2) _________ of an electrical appliance is defined as the
rate at which electrical energy is consumed by it.
Ans
: Wattage
3) The units of household consumption of electrical
energy are ______
Ans
: Kilowatt hour
3) One kilowatt hour =
Ans
: 36 x 10 5 watt second
4) According to
Joule’s law the amount of work done is directly proportional to ________
Ans
: heat produced
5) One Kilo Watt Hour (KWH) =
Ans
: 1000 Watt Hours
6) One Watt Hour =
Ans:
3600 Watt – Second
7) Electric Power (P) = Voltage x ________
Ans
: current
8) The S.I. unit of electrical energy is _________
Ans
: Joule
9) _______________ of an electrical appliance is defined
as the rate at which electrical energy is consumed.
Ans
: Wattage
10) A heater is marked 1000 W. The energy it consumes in an hour is
_________
Ans
: One KWH
11) The unit of household consumption of electrical
energy is _______
Ans
: KWH
12) A bulb of 40 watt is connected with 220 volts. The
current flowing through it ______
Ans
: 0.18 amp
13) A 200 W heater is used 6 hours daily and the cost of
one unit of electricity is 60 paise. The
cost of the energy consumed in the month of June is ________
Ans:
Rs.216/-
14) If a unit of electricity costs 80 paise, the cost of
consumption using ten lamps of each 60 watt in a month of 30 days is __________
Ans
: 90 KHW or Units
FARADAY’S LAWS OF ELECTROLYSIS :
1) Electro plating is a process of ________________ of
costlier or less corrodible metals on a base metal.
Ans:
coating a thin film
2) _____________ is a method of obtaining exact copy of
an engraved block containing letters or figures by the methods of electrolysis.
Ans
: Electro-typing
3) The vessel which contains an electrolyte and allows
electrolysis to take place is called a ________
Ans
: Voltameter or Electrolytic Cell
4) For refining and extracting metals ______ is used.
Ans:
electrolysis
MAGNETIC EFFECTS OF ELECTRIC CURRENT :
1) The direction of force (F) on the conductor in
Fleming’s Left Hand Rule is represented in ______
Ans
: Thumb
2) _______ Ammeter is used to measure the current in an
electric circuit.
Ans:
Ammeter
3) ___________ is used to measure potential difference .
Ans
: Voltameter
4) If a wire carrying current is bent in the form of a
circular loop, the magnetic field around the wire loop will be ___________ to
the plane of the wire.
Ans
: perpendicular
5) Ampere’s law concerned with the force on a wire
carrying a current in a ________ field.
Ans
: magnetic
6) Two parallel wires carrying current in the same
direction _______ each other.
Ans
: attract
7) Two parallel long conductors carrying current in the
opposite direction will ________
Ans
: repel
PRINCIPLE OF
WORKING OF AN ELECTRIC MOTOR:
1) Electric motor
converts electrical energy into _______
energy
Ans : mechanical
2)The rectangular
coil and iorn core in electric motor constitute_____
Ans : armature
3) RPM stands for
_________
Ans : rotations per minutes
4) An ___________
consists of a rectangular coil of permanent magnet two metallic half-rings and
an energy source.
Ans: electric motor
5) Current
carrying rectangular coil behaves as a __________
Ans: magnet
6) A current
carrying coil is subjected to a magnetic force, which rotates the coil
imparting it a ______ energy.
Ans : kinetic
7) If the coil is
made to rotate continuously, electric energy is converted into mechanical
energy such an arrangement is called an _______
Ans : electric motor
8) Commutator is
a device to reverse the direction of the _________
Ans : current
9) The commutator
rotates with the ________
Ans : Shaft
10) A.C. stands
for _______
Ans : Alternating Current
11) In A.C. motor
, there is no need for a ______ to reverse the current.
Ans: commutator
12) A D.C. motor
can have a efficiency less than _______
Ans : one
ELECTRO-MAGNETIC
INDUCTION:
1) Large amount
of electricity is produced with the help of machines called ________
Ans : dynamos or generators
2) Dynamo
converts mechanical energy into _______
Ans : electrical energy
3) A relative
motion of a magnet and a coil induces _____ in the coil
Ans : induced
4) The moving magnet
at higher speed causes the magnetic ________
Ans : flux
5) Dynamo works
on the principle of electromagnetic ________
Ans : induction
6) The
electricity that is supplied to our houhold appliance is generated by dynamos
at _______
Ans : hydroelectric stations
7) The phenomenon
of electromagnetic induction was discovered by ________
Ans : Faraday
8) A magnetic is
moved inside a coil of wire with its south pole moving inside the coil. Then the current flows through the coil in
the ______ direction.
Ans : clockwise
9) A magnet is
moved inside a coil of wire with its north pole moving inside the coil. Then
current flows through the coil in the ____ direction.
Ans : anticlockwise
10) An A.C.
current is one which varies periodically with time reversing the direction
every _____ cycle.
Ans : half
11) Rapid
rotating of the armature in the dynamo generates current or voltages in the
external circuit whose direction
alternates in each half cycle. Such current are called ________
Ans: alternating current
12) The
phenomenon of mutual inductance is utilized in the development of an electrical
device called _________
Ans: Transformer
13) A transformer
is an electric device which either increases or decreases the magnitude of an
_____ voltage by utilizing the phenomenon of electromagnetic induction.
Ans : alternating
14) A transformer
works on the principle of _____ using mutual inductance of two coils.
Ans : electromagnetic induction
15) All houses or
industries are connected in ____ in main supply.
Ans: parallel
16) The
transformer with number of turns in the secondary coil smaller than that in the
primary coil is called ______ transformer
Ans : Step-down
17) The
transformer with number of turns in the secondary coil larger than that in the
primary coil is called _____ transformer
Ans : step – up
18) Power
transmission is carried out in the form of high voltage and ______ current, so
that energy losses are reduced.
Ans : low
19) A transformer
uses ______ to minimize power losses
Ans : iron core
20) In a strep-up
transformer , voltage in the secondary coil increases and current ______
Ans : decreases
21) A transformer
works on _____ circuits only.
Ans : A.C.
22) In an ideal
transformer the input power is equal to ________
Ans : output power
23) The
efficiency of a transformer is always less than _______
Ans : one
24) A choke coil
has low inductance and ______ resistance
Ans : high
25) Domestic supply of voltage is ______
Ans : 220 volts
26) ________
transmission is carried out in the form
of high voltage and low current.
Ans : power
27) The bulk of
electricity is generated at ________
power stations
Ans hydro electric
28) In power
stations, mechanical energy is converted into ______ energy
Ans : electric
29) The
commercial generators work on the principle of a ________
Ans: dynamo
30) Electricity
is transmitted by a _____ system using pylon.
Ans : grid
31) Pylons are
high structures of towers to which _____ lines are connected
Ans : high tension or H.T.
32) A net work of
H.T. supply system in a region is called a ____ grid
Ans : power
33) In a step
down transformer the current _______
Ans : increases
34) For making
core of a transformer , the material is ______
Ans : soft iron
35) A transformer
uses _____ core to minimize power loss
Ans : iron
36) The feeder
stations in A.P. are ______
Ans : 150
37) The 33 K.V.
is supplied to about ____ stations
Ans : 50
38) The power
transmission utilizes _____ at different points on the transmission lines.
Ans : transformer
39) Eddy currents
are set up in a metallic block kept to
varying ______ field.
Ans : magnetic
40) Energy loss
due to eddy currents can be minimized in a transformer by laminating the core
of the ________.
Ans : transformer
41) A choke is a
coil of _________
Ans: Pure inductance
42) A choke is
used to limit an __________
Ans : alternating current
43) Which type
of current can be transmitted over a
long distances easily______
Ans : A.C.
44) For
electroplating we can use _______
Ans : D.C.
45) _______ is
used to convert mechanical energy into electrical energy
Ans : Dynamo or generator
46) A relative
motion of a magnet and coil induces ______ in the coil
Ans : current
47) The principle
of working of a dynamo is the law of _______
Ans : Electromagnetic induction
48) A _____ is a
electrical device which either increases or decreases the magnitude of an
alternating voltage.
Ans : transformer
49) A transformer
works on the principle of ______
Ans : electromagnetic induction
50) An example of
ohmic conductor is ______
Ans : copper wire
51) If 12 amperes
current is passed through a wire for 10 seconds, the amount of charge is ______
Ans: 120 coulombs
52) A charge of
480 coulombs is flowing in 2 minutes through an electric bulb. The current
flowing in the bulb is _____
Ans : 4 amp
53) On every day
a 60W bulb is used for 4 hours. The
amount of energy utilized in 30 days in kilowatt hours is _______
Ans : 7.2
54) An immersed
heater is connected to a line of 220 volts for half an hour. If it draws a current of 16.8 A, the heat
developed by it is ______
Ans : 1.584 x 106
calories
55) The
conversion of an A.C. into D.C. can be achieved by _________
Ans : a rectifier circuit
56) A transformer
works on the principle of ______ induction.
Ans : mutual
57) A transformer
uses iron core to ______
Ans : minimize losses
58) The unit of
self inductance is _________
Ans : Henry
PHYSICS – 4
MODER
PHYSICS
ATOMIC
STRUCTURE:
1) Atom of an
element , is electrically _________
Ans : neutral
2) The smallest
unit of element, which carries all the properties of the element is called an _______
Ans : atom
3) Who discovered
electrons?
Ans : J J Thomson
4) The electrons
in an atom revolve around the nucleus in circular orbits just like ______
revolve around the Sun.
Ans : planets
5) Rutherford
atomic model consists of ________ massive nucleus at the centre with electrons
revolving round it.
Ans: positively charged
6) The electron
has a _______ energy in a stationary
orbit.
Ans: definite
7) If an electron
jumps from lower stationary orbit to higher,
energy is ______
Ans : absorbed
8) When an
electron jumps from higher stationary orbit to lower energy orbit, energy is
_____
Ans : released
9) The space
between electron and proton is _______
Ans : vacuum
10) Proton is a
_________
Ans : positively charged
particle
11) Who
discovered protons ?
Ans : Rutherford and Goldstein
12) The alfa –
particle is a _______ charged particle
Ans : positively
ATOMIC NUMBER, ATOMIC MASS AND MASS DEFECT :
1) Atomic number
of an element indicates the number of _______ in an atom
Ans : protons or electrons
2) AMU stands for
_____
Ans : Atomic Mass Unit
3) Mass Number is
the sum of number of protons and number of _________
Ans: Neutrons
4) Neutron is
discovered by ____ in 1932
Ans : Chadwick
5) Neutron
is electrically ________
Ans : neutral
6) The number of
protons in an atom is defined as ____________
Ans : atomic number
7) The mass of an
atom is measured in ______
Ans : atomic mass unit or a.m.u.
8) ________ is
the difference between the sum of the individual masses of constituents in a
nucleus and the mass of the nucleus itself.
Ans : Mass defect
9) According to
Einstein mass energy relation ____________
Ans : E = Dmc2
10) Atomic number
is also called ______ number
Ans : proton
11) Atomic number
is denoted by _________
Ans : Z
12) Protons are
also equal to the number of ______ in a neutral atom
Ans : electrons
13) The mass of
one proton is ___________
Ans : 1.0078 a.m.u
14) The mass of
one neutron is __________
Ans : 1.0087 a.m.u.
15) An isotope
which is used in the determination of age of fossils is _________
Ans : Radio Carbon
16) Mass defect = ______________
Ans : ( sum of individual masses
of constituents – actual mass of the nucleus)
17) The relation
between mass and energy conversion was postulated by _______
Ans : Albert Einstein
18) Oxygen atom contains _________
Ans : 8 protons and 8 neutrons
RADIOACTIVITY:
1) The alpha –
particle is a __________ charged particle.
Ans : positively
2) The mass of
beta particle is the same as the mass of ________
Ans : electron
3) Isobars are
the elements with same mass _______
Ans : number
4) Ionising power
is highest in the case of ________
Ans : alpha – particles
5) Penetrating
capacity is highest for _______
Ans : gamma-rays
6) The
electromagnetic radiation observed in radio activity is ________
Ans : gamma – rays
7) Radioactivity
was discovered by _______
Ans : Henry Bequerel
8) Fluorescence
is the ability of certain substances to transform incident ultraviolet
radiation into ________ light.
Ans : visible
9) Uranium ore is
_____
Ans : Pitch blend
10) Alpha, beta,
gamma radiations are emitted by ________
Ans: radioactive nuclei
11) An alpha
particle is consists of two protons and two ________
Ans : neutrons
12) The speed of
alpha particles in air is ________
Ans : 10 7 m/s
13) Beta
particles are electrons originating in the _______
Ans: nucleus
14) Gamma rays
travel with the speed of ________
Ans : light
15) Gamma rays
are unaffected by __________
Ans : electric and magnetic
field
16) Gamma – rays
can easily destroy human _______
Ans : cells
17) Gamma rays
are used to kill cancer cells in the treatment of ______
Ans : Cancer
18) Radon is an
____ gas
Ans: inert
19) Alfa particle
is _____ charges particle.
Ans : positively
20) When alfa
particles is emitted, the atomic number of an atom increases _______
Ans : 2 units
21) Moderator in
a nuclear reactor reduces the _____ of the neutrons.
Ans : speed
22) Fusion
reactions take place in ________
Ans : Stars
23)
Uranium-235 is an isotope used in the
determination of ______
Ans : age of rocks
24)
Carbon-14 is an isotope used in the
determination of ______
Ans: age of fossils
25) The process
of transformation of one element into another artificial means of bombarding it
with high energy particles is known as _________
Ans : artificial transmutation
26) Artificial transmutation
was discovered by _______
Ans : Rutherford
27) Functioning
of the Thyroid gland can be tested by _______
Ans : 131- Iodine isotope
28) ______is process in which a heavy nucleon, when
bombarded with neutrons, splits into two nuclei of nearly equal mass with the
release of enormous amount of energy.
Ans : Nuclear fusion
29) Nuclear
fission was discovered by _____
Ans : Otto Hahn
30) An average of
_____ of energy is released per fission of an Uranium atom.
Ans : 200 MeV
31) A ______ is a
series of nuclear fissions whereby the neutrons produced in each fission cause
additional fissions.
Ans : Chain Reaction
32) The material
that slows down the neutrons in a nuclear reactor is called as __________
Ans: moderator
33) An
uncontrolled chain reaction occurs in __________
Ans : atom bomb
34) In nuclear
reactor control rods are made of ________
Ans : Cadmium or boron
35) ___________
is a reaction in which light nuclei are combined together to form a heavier
product nucleus with the use release of enormous amount of energy.
Ans : Fusion
36) A radioactive
isotope is called a radio _____
An s: isotope
37) Radioactive
cobalt is used to detect internal ______ in the cast material
Ans : flaws
38) Radio carbon
dating is done by estimating in the specimen by the ratio of ______
An s: C-14 / C-122
39) The radio
isotope used to cure cancer is _______
Ans : Cobalt isotope
40) In U-235
chain fission, chain is installed by a ______
Ans : neutron
41) Nuclear
fusion is opposite to ______
Ans : nuclear fission
42) Radio
isotopes formed by nuclear transmutation are rarely found in nature because
they have very short _____ period.
Ans : half life
43) The fusion
reactions require high temperatures, are also called _______
Ans : thermo nuclear
reactions.
44) The _____
cycles are responsible for energies of the stars like the Sun.
Ans : proton
45) The principle
of hydrogen bomb is _____________
Ans : uncontrolled fusion
reaction
46) The material
that slows down the neutrons in a nuclear reactor is called ______
Ans : moderator
47) The fuel used
in a nuclear reactor is _____________
Ans : Uranium – 235
48) The
projectiles used in a fission of U-235 are ________
Ans : neutrons
49) The relation
between mass and energy was postulated by _______
Ans : Albert Einstein
50) The reason
for using cadmium rods in nuclear reactor is ________
Ans : to absorb neutrons
51) The time
taken by radioactive element to disintegrate completely ________
Ans : infinite
52) In a nuclear
reactor cadmium is used as a _________
Ans : Control Rod
53) In a nuclear
reactor, graphite is used as ___________
Ans : moderator
54) In a nuclear
reactor entire region of a fuel elements is known as ________
Ans : Reactor core
PHYSICS – 5
ELECTRONICS
Band Theory of
Solids :
1) Rubber is
__________
Ans : Insulator
2) A very poor
conductor of electricity is called an _______
Ans : Insulator
3) Metals are
______ of electricity
Ans : good conductors
4) The energy gap
of conductor is ______
Ans : zero
5) The
conductivity of a semiconductor depends on its _________
Ans : temperature
6) The absence of
an electron is the valence band of a semiconductor is called a _______
Ans : hole
7) Hole is a
_______ charge carrier of current
Ans : positive
8) Both holes and
electrons are the _______ in a semiconductor
Ans : charge carriers
9) Semi –
conductors are classified in to how many types?
Ans : Two
10)
Semiconductors are classified into two type. They are_____
Ans : 1) Intrinsic 2) Extrinsic semiconductors
11) Insulators
are _____ conductors of electricity.
Ans : poor
12) Insulators
are poor conductors of electricity because the energy gap is relating
large and the concentration of ____ is
small
Ans : electrons
13) Substances
that conduct electricity are known as ______
Ans : electric conductors
14) The flow of
______ constitutes an electric current
Ans : electron
15) An example
for p-type semi-conductor is _____
Ans : Silicon with Aluminium as
impurity
16) The number of
free electrons are more in _________
Ans : copper
17) The energy
gap is highest in the case of _______
Ans : insulator
18) When
temperature of a semi-conductor is raised, the energy gap _______
Ans: decreases
19) By whom the charge carried in a semi-conductor
Ans : electrons and holes
INTRINSIC AND
EXTRINSIC SEMI-CONDUCTORS:
1) Purre
semiconductors are called _____ semi-conductors
Ans: intrinsic
2) In n-type
semiconductor the majority carriers are ________
Ans: electrons
3) To make
silicon a p-type semiconductor, the impurity to be doped is ______
Ans : aluminium
4) Introducing
impurities in very small quantities into
a material is called ______
Ans : doping
5) ______ semi
conductors are the semiconductors doped with desired impurity.
Ans : Extrinsic
6) Depending on
the type of impurity extrinsic semi-conductors are how many types?
Ans : Two types
1) p-type
2) n-type
7) Trivalent
impurities are called ________
Ans :acceptors
8)
Pentavalent impurities are called
________
Ans : donors
9)
Phosphorous is a _________ impurity
Ans : pentavelent
10) Aluminium is
a _____ impurity
Ans : trivalent
11) p-type and
n-type semi-conductors are electrically______
Ans : neutral
12) An example
for intrinsic conductor is ________
Ans : germanium
13) A
semiconductor acts as an insulator at _______
Ans : 0° K
14) The charge
carriers in a semiconductor are ________
Ans : electrons and holes
JUNCTION
DIOIDE-PROPERTIES AND USES:
1) A Diode offers
______ resistance under reverse bias condition
Ans : high
2) In rectifier
circuits _____ are used.
Ans: diodes
3) p-type
semi-conductor has excess number of _______
Ans : holes
4) n-type semi –
conductor has excess number of _______
Ans : electrons
5) LED means
______
Ans : Light Emitting Diode
6) What is Diode?
Ans : It is a rectifier
7) ______ are
used in digital clock and digital calculators
Ans: LEDs
8) LEDs _____ on
supply of current
Ans: glrow
TRANSISOTRS –
PROPERTIES AND USES:
1) The three
terminals of a transistors are called ___________ and ________
Ans : Emitter, base,
collector
2) Transistors
are used in ________ which produce signals of different frequencies.
Ans : oscillators
3) The transistor
was invented by _________
Ans : J.Bardeen, W.H.Brattain
and William Shockley
4) The transistor
is a small semi-conductor device which is at the _____ of the modern day
electronic appliances.
Ans : heart
5) A transistor
is a combination of two _____ joined back to back.
Ans : diodes
6) A transistor
consists of 3 terminals namely, emitter, base and _______
Ans : collector
7) I.C. stands
for ________
Ans : Integrated Circuits
8) Integrated
circuits are called ____
Ans : Chips
9) Transistor act
as _________
Ans : amplifier
10) Chips are
important in the ______
Ans: micro electronic systems
RADIO AND
TELEVISION – BASIC PRINCIPLES OF WORKING :
1) r.f. stands
for _________
Ans : Radio frequency
2) The process of
fixing messages to r.f. carrier waves is called __________
Ans : modulation
3) A.M. is the
abbreviation for ___________
Ans : Amplitude Modulation
4) At home the
r.f. modulated carrier wave is received by _________
Ans : aerial or antenna
5)
Electromagnetic waves in radio frequency range are used for _____ and ______
communication.
Ans : Radio and
R.V.
6) FM is the
abbreviation for _________
Ans : Frequency Modulation
7) The process of
extracting information from the modulated r.f. carrier waves is called ________
Ans : demodulation
8) ________
produces electromagnetic waves of different frequencies
Ans : Induction coil
9) For radio
communication the range of carrier frequency is from about ______
Ans : 300 KHz to 30 MHz
10) For
television communication frequency range of carriers is from about ________
Ans : 30 MHz to 300 MHz
11) Modulated waves are sent into space by a ________
Ans : transmitting antenna
12) The three
states in radio or TV communication are
________
Ans : 1) production of
messages 2) transmission 3) detection
13) _______
modulate r.f. waves carrying messages
Ans : Transmitters
14) ______ is a
process of dividing an image on the screen into a large number of very small
squares formed by sets of horizontal and vertical straight lines.
Ans : Scanning
15) Tuning
circuits are also called as _______
Ans : Channel selector
16) TV is known
as ______
Ans : Kinescope
17) _______ is a
camera consisting of a cathode ray beam and
a photo cell.
Ans : Iconoscope
18) Now a days
______ is used for scanning prupose.
Ans : Iconoscope
19) Induction
coil produces ______ waves of different frequencies
Ans : Electromagnetic (EM)
20) Radio waves
travel through _______ over a long distances and can be used as carriers of
messages
Ans : space
21) Messages are
converted into ______ signals
Ans : electrical
22) Electrical
signals re superimposed on _______
Of suitable high (radio)
frerquency
Ans : electromagnetic waves
23) The
frequencies used in TV communications are in the range of 30 MHz to _____
Ans : 300 MHJz
24) The name of
the camera which consists of a cathode ray beam and photocell is _______
Ans : Iconoscope
COMPUTER –
BASIC PRINCIPLES OF WORKING :
1) IC means________
Ans : Integrated Circuit
2) Key board is
an _______
Ans :Input device
3) A set of
_______ is called a programme
Ans : instructions
4) A CPU consists
of ______________
Ans : Control Unit (CU), Memory,
Arithmetic Logic Unit(ALU)
5) A ______
language is independent of machine
Ans : high level
6) ASSEMBLER is a
______ language
Ans : machine
7) A semi
conductor consisting of combinations of large number o f diodes and
transistors in it is called ___________
Ans : Integrated Circuit or Chip
8) A _______ is a
combination of ICs
Ans : Microprocessor
9) Data and instructions are supplied to the
computer through an _______
Ans : Input device
10) CPU means
________
Ans : Central Processing Unit
11) Printer is an
_______
Ans : Output device
12) _______ is
the heart of the computer
Ans : CPU
13) The number
system, consists of only two digits 0 and 1 is called ______ system
Ans : binary
14) A binary
digit either 1 or 0 is called a ______
Ans : bit
15) In BCD code the first four bits are called Zero bits and the remaining
four bits are called _____ bits
Ans : numeric
16)
___________language is internal language of the computer
Ans: Machine
17) Machine
language depends on ______ of a computer
Ans : Hardware
18) BASIC is a
________ language
Ans : high level
19) A Compiler translates
________________________________
Ans : a high level programme to
machine language instructions
20) Computer
programme can be written in ___________ language
Ans : high level
21) All the
physical components like CPU input and output devices put together are called
_____ of the computer
Ans : Hardware
22) The
electronic circuits are called _________
Ans : logic circuits
23) A combination
of ICs is called a __________
Ans : microprocessor
24) Data and
instructions are supplied through an ________
Ans : input devices (like Keyboard, mouse, Scanner, Camera, Joy
Stick etc.)
25) The
microprocessor (Chip) also consists of a
second component called _______
Ans : Memory
26) the last
component of the microprocessor (Chip) is called ________
Ans : Arithmetic Logic Unit
(ALU)
27) The Printer
or a visible screen is called ______
Ans : Monitor
28) The output
device is _________
Ans : Monitor
29) The combination
of CU, Memo and ALU is _________
Ans : CPU or Central Processing
Unit
30) A computer
uses a number system different from our ______ system
Ans: decimal
31) The number
system consists of two digits i.e., zero and ________, in computers
And : one
32) The digit
zero or one is called _________
Ans : bit
33) In BCD , the
4 bits are called ____________
Ans : Zonal bits
34) The function
of a Compiler is to _____________
Ans : translate the high
level language instructions into machine
language
35) Byte is
formed by __________
Ans : a group of 8 bits
36) A set of
instructions is called a __________
Ans : programme
CHEMISTRY
& INDUSTRY:
1) Cement
is a mixture of _________
Ans : Calcium Silicate and aluminates
2) Glass –
blowing is possible with _______
Ans : Pyrex glass
3) Terra –
cotta articles are _______
Ans : Porous
4) Which
gives colour to the fibre?
Ans : Chromophore
5) Chief
component of cooking gas (LPG) is ____
Ans : Butane
6)
_________________ gives blue colour to the glass
Ans: Cobalt oxide
7) The
chemical composition of talc is ____
Ans : Magnesium silicate
8) What is
insulin ?
Ans : It is a harmone
9) For
making bottles, which type of glass is used ?
Ans : Soda Glass
10) For
making optics, which type of glass is used ?
Ans : Flint glass
11) For
making laboratory glassware, which type of glass is used ?
Ans : Pyrex glass
12)
Cooking gas is known as ____
Ans : LPG (Liquid Petroleum Gas)
13)
Example of natural manure is _____
Ans : Compost
14) Glass is
a mixture of _______
Ans : sodium silicate, calcium
silicate and sand
15) The
natural gas is _______________
Ans: methane ( CH4)
16)
Another name of petrol is ________
Ans: Gasoline
17)
Domestic Gas Cylinder contains a mixture of ____________
Ans : Propane, Butane and Propine
18)
Shaving soap contains excess of ___________
Ans : Stearic acid
OILS
& FATS:
1)
Detergents are used even in _______ because Ca+ and Ma+2 react with hard water
ions but do not form precipitate
Ans : Hard Water
2) Examples
for saturated fatty acids?
Ans : Lauric, Myristic, Palmitic,
Stearic acids
3)
Examples for Unsaturated fatty acids?
Ans : Myriscoleic, Palmitoleic, Oleic,
Linoleic, Linoleinic acids
4)
Hydrogenation of oils give _____
Ans : Fats (Vanaspathi)
5) How
Dalda(Vanaspathi) is manufactured ?
Ans : Dalda is a fat obtained by the
catalytic hydrogenation of vegetable oil
6) Soaps
are ____________
Ans : sodium salt or potassium salt of
fatty acid of long carbon chains
7) Soaps
contain 30% of _______
Ans : water
8)
Detergents differ from soap in their action with __________
Ans : Hard water
9)
Detergents are ___________
Ans: sodium salts of alkyl benzene
sulphonates or fatty alcohol sulphates
10) No.
of amino acids known so far _______
Ans : 26
CARBOHYDRATES AND PROTEINS :
1)
Sweetest sugar is_____________
Ans : Fructose
2) The
sugar content of molasses is _____
Ans : 50%
3)
Consumption of denatured spirit causes __
Ans : Unconsciousness
4) Sukrose
is broken down into _____ and ______ during fermentation.
Ans: Glucose , fructose
5)
_______________ enzyme breaks the sucrose.
Ans : Invertase
6) Beer is
made from ____
Ans : Barley
7)
Non-sugars are found in ________
Ans : rice, pulses and potato
8) Starch
and cellulose are examples of _________
Ans : polysaccharides
9)
Cellulose in the form of cotton is useful for _________
Ans : our clothing
10) Starch
is tested by which solution ?
Ans : iodine solution
11) Iodine
solution turns starch solution into _____ in colour
Ans : blue
12) The
sugar of our daily use, is mainly obtained from ________
Ans : sugar cane
13)
Sugarcane contains 11 – 15% of ______ by weight.
Ans : sucrose
14) Line
is added to neutralize sugar cane juice in ________
Ans : sugar industry
15) Which
is called as mother liquor ?
Ans : Molasses
16) Ethyl
alcohol is produced by fermentation of molasses by ______
Ans : yeast
17)
Consumption of denatured spirit causes ____________
Ans: blindness and death
18) Ethyl
alcohol mixed with pyridine or methyl alcohol is called as ______
Ans : denatured spirit
19) Amino
acids are building blocks of _________
Ans : Proteins
20)
Essential amino acids must be supplied to human body through ______ only
Ans : diet
21) Out of
26 amino acids, human body cannot
synthesise how many amino acids ?
Ans : Nine amino acids. These nine amino acids are also called as
essential amino acids
22) Sickel
cell haemoglobin causes a disease called as _______________
Ans : Sickle cell anemia
23) Which
is present in skin, hair, nails, wool, horn, and feathers?
Ans :Keratine
24) Which
regulates blood sugar level ?
Ans : Insuline
25) The
beverage which contains high percentage of alcohol is _______
Ans : brandy
CHEMISTRY OF CARBON COMPOUNDS:
1) The refractive index of diamond is ____
Ans : 2.45
2) The chemical name of washing soda is _______
Ans : sodium carbonate
3) In diamonds and graphites which is common ?
Ans : Carbon
4) The occurrence of same element in two or more different forms I called
as ________
Ans : allotropy
5) Diamond reflects light falling on it , making it shine. What is the
reason ?
Ans : refractive index
6) Why diamond is used as glass cutter ?
Ans : due to its hardness
7) Graphite is used as ______
Ans : lubricant
8) Which gas accumulates in caves and mines ?
Ans : Carbon dioxide (
because carbondioxide is heavier than air )
9) Carbon dioxide is soluble in _______
Ans : Water
10) Carbon dioxide is used in the preparation of ____________
Ans : Soda water and cool
drinks
11) Which gas is used as fire extinguisher ?
Ans: Carbon dioxide
12) Coal deposits are called as ______
Ans: Store of Sun
13) Anthracite coal contains 95% of ________
Ans : carbon
14) The commonest variety of coal is __________
Ans : bituminous coal or
stone coal
15) Bituminous coal contains ________ of carbon.
Ans : 82%
16) Lignite coal contains how much of carbon ?
Ans : 70%
17) Ethyne is commonly known as _________
Ans : acetylene
18) Acetylene is used in __________
Ans : welding, artificial
ripening of fruits
19) The allotrope of carbon which has tetrahedral structure is
___________
Ans : Graphite
20) Polythene is obtained from ethylene by the __________
Ans : poluymerization
ACIDS, BASES AND SALTS :
1) What is colour of methyl orange indicator in acidic medium ?
Ans : Red
2) What is the colour of phenolphthalein indicator in basic solution?
Ans : Pink
3) The pH (point of hydrogen) of gastric juice is__________
Ans : 1 – 2
4) The pH of acids is in the range of ______
Ans : 0 to 7
5) The pH of bases is in the range of _______
Ans : 7 to 14
6) Human blood pH is _______
Ans : more than 7 (i.e., 7.32 to 7.45)
7) Acids turn blue litmus to ______
Ans : red
8) Bases turn red litmus to ______
Ans : blue
9) pH was introduced by ______
Ans : Sorensen
10) pH of pure water is ________
Ans : 7
11) pH of urine is _______
Ans : 4.8 to 7.5
12) Acids reacts with metal and gives _______
Ans
: hydrogen
SOLUTIONS:
1) The common name of so0dium thiosulphate is _______
Ans : hypo
2) Soda is a solution of carbondioxide in ______
Ans : water
3) Naphthalene dissolves in ________
Ans : Kerosene
4) Naphthalene is not soluble in _____
Ans : Water
5) Sodium chloride in water is ___________
Ans : strong electrolyte
ALKALINE EARTH METALS :
1) Carnalite is one of ore of _____
Ans : magnesium
2) Epson salt is the mineral of ______
Ans : magnesium metal
3) Magnesium reacts with _______
Ans : Hot water
4) Radium is a _______
Ans : radioactive element
5) The element which gives dazzling light (Deepavali crackers) when burnt
in air is _____
Ans : Magnesium
6) Dolomite is the mineral of _______
Ans : magnesium
PERIODIC CLASIFICATIN OF ELEMENTS:
1) Mendeleef’s periodic table is based on the _________
Ans : atomic weight
2) Eka aluminium is _______
Ans : gallium
3) Eka boron is _____
Ans : scandium
4) Removal of hydrogen is called as _____
Ans: oxidation
5) Addition of hydrogen or removal of oxygen is called as ______
Ans : reduction
6) The first classification of elements is attempted by _____
Ans : Dobereiner
CHEMICAL BOND:
1) Complete transfer of electrons from one atom to another leads to the
formation of _______
Ans : ionic bond
2) Oxygen has _____ lone pairs of electrons in water molecule
Ans : two
3) Water molecule has ______
shape bond. Water
molecule is in non-linear bond.
Ans : ‘V ‘ (English letter V)
4) Ammonia molecule has _______
shape bond.
Ans : pyramidal
ATOMIC STRUCTURE :
1) Bohr’s theory is valid for ___________
Ans : any atom or ion
having one electron
2) The scientist who invented elliptical orbits is _________
Ans : Sommerfield
3) Rutherford proposed planetary model based on his ________ scattering
experiment.
Ans : alfa – ray
4) Quantum theory of radiation is proposed by ________
Ans : Max planck
5) Electron was discovered by ________
Ans : J .J.Thomson
6) The nucleus of an atom is made up of protons and neutrons and so they
are known as ____
Ans : nucleons
7) Rutherford’s model of atom is also known as planetary model or ______
model.
Ans : nuclear
8) The splitting of spectral lines when atom is put in magnetic field is
called ______
Ans : Zeeman’s effect
9) Atomic sizes are expressed in ______ units.
Ans : Angstrom
10) An alfa particle consists of _________
Ans : two protons, two
neutrons
11) The element having no neutron in its nucleus is ________
Ans : Hydrogen
12) Chadwick discovered _______
Ans : neutrons
13) Who discovered protons ?
Ans : Rutherford and
Goldstein
14) Hydrogen atom gets stability
by achieving the configuration of ________
Ans : Helium