Physics 100 Important Questions and Answers
S.No
|
Question
|
Answer
|
1
|
Who firstly demonstrated
experimentally the existence of electromagnetic wave?
|
Hertz
|
2
|
The working of the quartz
crystal in the watch is based on which effect?
|
Piezoelectric Effect
|
3
|
What is te the unit of
Radioactivity?
|
Curie
|
4
|
What is the wavelength of
visible spectrum?
|
390-700 nanometres
|
5
|
One astronomical unit is
the average distance between___?
|
Earth & Sun
|
6
|
Number of basic S.I.
units is ___.
|
Seven (7)
|
7
|
What is the name of the
scientist who stated that matter can be converted into energy?
|
Einstein
|
8
|
The size of atomic
nucleus is of the order of___?
|
10^-14 m
|
9
|
A
temperature at which both the Fahrenheit and the centigrade scales have the same
value?
|
-40°
|
10
|
In the visible spectrum
which colour has the shortest wavelength?
|
Violet
|
11
|
What is the unit of
specific resistance?
|
Ohm-metre
|
12
|
What do we use as a
moderator in nuclear reactor?
|
Graphite
|
13
|
The mirror used in motor
vehicles near the driver's seat is a__?
|
Convex Mirror
|
14
|
Electron microscope was
invented by__?
|
Robert Koch
|
15
|
The hydraulic brake used
in automobiles is a direct application of__?
|
Pascal's Law
|
16
|
The filament
of an electric bulb is made of which metal?
|
Tungsten
|
17
|
Camberts Law is related
to__?
|
Interference
|
18
|
Which waves are used in
sonography?
|
Ultrasonic waves
|
19
|
Which instrument is used
to measure the power of electric circuit ?
|
Wattmeter
|
20
|
Splitting of Uranium
nucleus releases_____ energy.
|
Nuclear
|
21
|
kilowatt hour is the unit
of__?
|
Energy
|
22
|
A simple device that is
used to either break or complete the electric circuit, is called _____?
|
Switch
|
23
|
Where the value of ‘g’
(acceleration due to gravity) is maximum?
|
At poles
|
24
|
Good conductors have many
loosely bound __?
|
Electrons
|
25
|
If the body is hollow,
then its centre of gravity lies?
|
outside the material
|
26
|
A man with a dark skin,
in comparison with a man with a white skin, experiences__?
|
Less heat, Less cold
|
27
|
What is the escape
velocity for all objects from the earth?
|
11.16 km/sec
|
28
|
If the temperature inside
a room is increased, the relative humidity will?
|
Decrease
|
29
|
If a bar magnet is cut
length wise into 3 parts, what will the total number of poles be?
|
6
|
30
|
Light travels in a____?
|
Straight line
|
31
|
What converts the
alternating current into direct current?
|
Rectifier
|
32
|
Einstein got noble prize
for____?
|
Photoelectric Effect
|
33
|
The nucleus of an atom
consists of__?
|
Neutrons and protons
|
34
|
What is the measuring
unit of length of light waves?
|
Angstrom
|
35
|
How
much is one barrel of oil approximately equal to?
|
159 litres
|
36
|
The sky appears black
from the moon because of___?
|
Lack of Atmosphere
|
37
|
The specific resistance
of a wire varies with its___?
|
Material
|
38
|
Which instrument is used
to measure depth of ocean ?
|
Fathometer
|
39
|
The unidirectional
property of a pn-junction is useful for its use as which thing?
|
Rectifier
|
40
|
The strongest force in
the nature is ____?
|
Nuclear Force
|
41
|
Which is the only natural
magnet?
|
Magnetite
|
42
|
We cannot see during a
fog, because of ____.
|
Scattering of light
|
43
|
In which medium sound travels faster ?
|
Solid
|
44
|
A fast wind can turn the
blades of a windmill because it possesses__.
|
Potential Energy
|
45
|
Which of the following
material is used for electric wire heater?
|
Nichrome
|
46
|
Conversion of chemical
energy into electrical energy occurs in which thing?
|
Battery
|
47
|
The direction of a
magnetic field within a magnet is___?
|
From South to north
|
48
|
What remains constant
while throwing a ball upward?
|
Acceleration
|
49
|
What type of lens is a
magnifying glass?
|
Convex lens
|
50
|
Why does a liquid drop
tend to assume a spherical shape?
|
To minimize surface
tension
|
51
|
What happens when soda water bottle falls freely?
|
No bubbles form
|
52
|
Pure water freezes at
what temperature?
|
32 F
|
53
|
Why are Metals good
conductor of heat than insulator?
|
they contain free
electrons
|
54
|
When some detergent is added to water, the surface
tension___?
|
Decreases
|
55
|
The value of which
quantity remains same in all system of units?
|
Specific Gravity
|
56
|
Distance of stars are
measured in___?
|
Light Years
|
57
|
Nature of sound wave is
____?
|
Longitudinal
|
58
|
Which is used to initiate
fissions ?
|
Neutrons
|
59
|
The total internal reflection can occur when light pass
from___.
|
Denser to Rarer medium
|
60
|
Who discovered Diode Bulb
?
|
Sir J. S. Fleming
|
61
|
Radio waves of constant
amplitude can be generated with___?
|
Oscillator
|
62
|
What is the SI unit of
luminous intensity?
|
Candela
|
63
|
What is the name of short
duration wave?
|
Pulse
|
64
|
The absorption of ink by
blotting paper involves___?
|
Capillary Action
|
65
|
Two drops of a liquid are
merged to from a single drop. In this process___?
|
Energy is released
|
66
|
Which is more elastic -
Steel or Rubber?
|
Steel
|
67
|
An atom bomb is based on
the principle of___?
|
Nuclear Fission
|
68
|
Which instrument is used
to measure the scattering of light by particles suspended in a liquid ?
|
Nephetometer
|
69
|
The speed of light with
the rise in the temperature of the medium ___?
|
Remains unaltered
|
70
|
Most commercial nuclear
power plants worldwide are cooled by __?
|
Water
|
71
|
Electric Motor
converts____?
|
Electric energy to
mechanical energy
|
72
|
Nuclear sizes are
expressed in a unit named____?
|
Fermi
|
73
|
Weightlessness experienced in a spaceship is due to___?
|
Absence of Gravity
|
74
|
The blue colour of the
clear sky is due to ____?
|
Dispersion of Light
|
75
|
What does airbag, used
for safety of car driver, contain?
|
Sodium Azide
|
76
|
Radian is used to measure___?
|
Angle
|
77
|
Who had showed that the
electric and magnetic waves are equal in vacuum?
|
James Clerk Maxwell
|
78
|
When a red glass is heated in dark room it will seem___.
|
Green
|
79
|
The friction force exerted by fluids is called ___.
|
Drag
|
80
|
Which is used in
designing ships and submarines?
|
Archimedes Principle
|
81
|
Which instrument is used
to measure change in volume of substances ?
|
Dilatometer
|
82
|
On which principle ,
transformer works?
|
Mutual Induction
|
83
|
Potential energy of your body is minimum when you
_______.
|
Lie down on ground
|
84
|
The velocity of sound in air___?
|
332m/sec
|
85
|
Beats occur because of
__?
|
Interference
|
86
|
In summer, the mirages are seen due to the phenomenon of
__?
|
Total Internal Reflection
|
87
|
Who gave the first experimental value of G?
|
Cavendish
|
88
|
Astigmatism can be
corrected by__?
|
Cylindrical lenses
|
89
|
What apparatus is used to
locate a submerged object?
|
SONAR
|
90
|
The image formed by convex
lens in a simple microscope is__.
|
Virtual & Erect
|
91
|
What is the unit of magnetic flux?
|
Maxwell
|
92
|
Coolis tube is used to produce___?
|
X-Rays
|
93
|
Sudden fall in barometer is indication of___?
|
Storm
|
94
|
Force of attraction between the molecules of different
substances is called___?
|
Adhesive Force
|
95
|
What is the working principle of Washing machine?
|
Centrifugation
|
96
|
Insects can move on the
surface of water without sinking due to___.
|
Surface tension of water
|
97
|
The temperature of the
sun is measured with ___.
|
Pyrometer
|
98
|
Acceleration acts always in the direction__?
|
of the net force
|
99
|
Which instrument is used to measure altitudes in
aircrafts ?
|
Altimeter
|
No comments:
Post a Comment