Physics Multiple Choice Questions with Answers:-
1. In terms of magnetic properties, oxygen belongs to?
a. Magnetic Materials
b. Ferromagnetic materials
c. Paramagnetic materials
d. Diamagnetic materials
ANSWER :
c. Paramagnetic materials
2.What will happen if the star having a mass greater than five times of the sun is dead?
a. The white dwarf will form
b. Neutron star will form
c. The black hole will form
d. Nebula will form
ANSWER :
c. The black hole will form
3. A current I flows through a potential difference V in an electrical circuit containing a resistance R. The product of V and I i.e., I may be understood as
a. resistance R
b. heat generated by the circuit
c. thermal power radiated by the circuit
d. rate of change of resistance
ANSWER :
c. thermal power radiated by the circuit
4. In general, what is the range of frequency of the “Message Signal”?
a. Radio Frequency
b. Audio Frequency
c. Both ‘a’ and ‘b’
d. Neither ‘a’ nor ‘b’
ANSWER :
a. Radio Frequency
5. Gravitational force shares a common feature with the electromagnetic force. In both cases, the force is
a. between massive and neutral objects
b. between charged objects
c. a short range
d. a long range
ANSWER :
a. between massive and neutral objects
6. Radiocarbon is produced in the atmosphere as a result of
a. collision between fast neutrons and nitrogen nuclei present in the atmosphere
b. the action of ultraviolet light from the sun on atmospheric oxygen
c. the action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere
d. lightning discharge in the atmosphere
ANSWER :
a. collision between fast neutrons and nitrogen nuclei present in the atmosphere
7. It is easier to roll a stone up a sloping road than to lift it vertical upwards because
a. work done in rolling is more than in lifting
b. work done in lifting the stone is equal to rolling it
c. work done in both is the same but the rate of doing work is less in rolling
d. work done in rolling a stone is less than in lifting it
ANSWER :
d. work done in rolling a stone is less than in lifting it
8. The absorption of ink by blotting paper involves
a. the viscosity of ink
b. capillary action phenomenon
c. diffusion of ink through the blotting
d. siphon action
ANSWER :
b. capillary action phenomenon
9. Siphon will fail to work if
a. the densities of the liquid in the two vessels are equal
b. the level of the liquid in the two vessels are at the same height
c. both its limbs are of unequal length
d. the temperature of the liquids in the two vessels are the same
ANSWER :
b. the level of the liquid in the two vessels are at the same height
10. Large transformers, when used for some time, become very hot and are cooled by circulating the oil. The heating of the transformer is due to
a. the heating effect of current alone
b. hysteresis loss alone
c. both the heating effect of current and hysteresis loss
d. intense sunlight at noon
ANSWER :
c. both the heating effect of current and hysteresis loss
11. Which one of the following phenomena shows the particle nature of light?
a. Polarisation
b. Photo-electric effect
c. Interference
d. Refraction
ANSWER :
c. Interference
12. What is the function of a microphone?
a. Convert sound signals to electric signals
b. Convert electric signals to sound signals
c. Convert sound signals to electromagnetic waves
d. None of the above
ANSWER :
a. Convert sound signals to electric signals
13.Which one of the following is deviated by an electric field?
a. a – rays
b. ? – rays
c. Neutrons
d. X – rays
ANSWER :
a. a – rays
14. Which one among the following lasers is used in cancer treatment?
a. He-Ne laser
b. Ruby laser
c. CO2 laser
d. Semiconductor laser
ANSWER :
c. CO2 laser
15. Modern movie songs released are the best in quality of sound. The rich quality of sound is due to which one of the following?
a. A note of high-frequency
b. A note of high amplitude
c. Consists of many harmonics
d. Consists of the fundamental frequency
ANSWER :
c. Consists of many harmonics
16. Nuclear sizes are expressed in a unit named
A. Fermi
B. angstrom
C. Newton
D. tesla
ANSWER :
A. Fermi
Explanation:
Fermi – A unit of length equal to 10-15 meter (one femtometer), used in nuclear physics. It is similar to the diameter of a proton.
17. A light-year is a unit of
A. time
B. distance
C. light
D. intensity of light
ANSWER :
B. distance
18. Mirage is due to
A. unequal heating of different parts of the atmosphere
B. magnetic disturbances in the atmosphere
C. depletion of the ozone layer in the atmosphere
D. equal heating of different parts of the atmosphere
ANSWER :
A. unequal heating of different parts of the atmosphere
19. Light from the Sun reaches us in nearly
A. 2 minutes
B. 4 minutes
C. 8 minutes
D. 16 minutes
ANSWER :
C. 8 minutes
20. Stars appear to move from east to west because
A. all stars move from east to west
B. the earth rotates from west to east
C. the earth rotates from east to west
D. the background of the stars moves from west to east
ANSWER :
B. the earth rotates from west to east
21. The impurity atom with which pure silicon should be doped to make a p-type semiconductor are those of
a. Phosphorus
b. boron
c. Antimony
d. Arsenic
ANSWER :
b. boron
22. Which one of the following planets is said to be “twin sister” of the earth?
a. Mercury
b. Venus
c. Mars
d. Jupiter
ANSWER :
b. Venus
23. The spread in colors in a rainbow on the sky is primarily due to
a. The desperation of sunlight
b. refraction of sunlight
c. Reflection of sunlight
d. total internal reflection of sunlight
ANSWER :
c. Reflection of sunlight
24. Who among the following gave the first experimental value of G?
a. Cavendish
b. Copernicus
c. Brook Taylor
d. Albert Einstein
ANSWER :
a. Cavendish
25. Light Emitting Diode (LED) converts
a. Light energy into electrical energy
b. Electrical energy into light energy
c. Thermal energy into light energy
d. Mechanical energy into electrical energy
ANSWER :
b. Electrical energy into light energy
26. Pa(Pascal) is the unit for
A. thrust
B. pressure
C. frequency
D. conductivity
ANSWER :
B. pressure
27. Planets do not twinkle because
A. they emit light of a constant intensity
B. their distance from the earth does not change with time
C. they are very far away from the earth resulting in a decrease in intensity of light
D. they are nearer to earth and hence we receive a greater amount of light and, therefore minor variations in the intensity are not noticeable
ANSWER :
D. they are nearer to earth and hence we receive a greater amount of light and, therefore minor variations in the intensity are not noticeable
28. Metals are good conductors of electricity because
A. they contain free electrons
B. the atoms are lightly packed
C. they have a high melting point
D. All of the above
ANSWER :
A. they contain free electrons
29. Let a thin capillary tube be replaced with another tube of insufficient length then, we find water
A. will overflow
B. will not rise
C. depressed
D. change its meniscus
ANSWER :
B. will not rise
30. Out of the following pairs, choose the pair in which the physical quantities do not have identical dimension?
A. Pressure and Young’s modulus
B. Planck’s constant and Angular momentum
C. Impulse and moment of force
D. Force and rate of change of linear momentum
ANSWER :
C. Impulse and moment of force
31. Which of the following has the least penetrating power?
a. a – particles
b. ß – particles
c.? – particles
d. None of these
ANSWER :
a. a – particles
32. When a red glass is heated in dark room it will seem
a. Black
b. Green
c. Yellow
d. Red
ANSWER :
b. Green
33. Which one of the following causes a greenhouse effect?
a. Cosmic rays
b. Ultra-violet rays
c. Infrared rays
d. Radio waves
ANSWER :
c. Infrared rays
34. If there were no gravity, which of the following will not be there for a fluid?
a. Viscosity
b. Pressure
c. Archimede’s upward thrust
d. Surface tension
ANSWER :
b. Pressure
35. The Celsius temperature is a/an
a. Relative temperature
b. Absolute temperature
c. Specific temperature
d. Approximate temperature
ANSWER :
c. Specific temperature
36. If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then both bodies acquire the same
a. velocity
b. momentum
c. acceleration
d. kinetic energy
ANSWER :
b. momentum
37. Pick out the scalar quantity
a. force
b. pressure
c. velocity
d. acceleration
ANSWER :
b. pressure
38. Rectifiers are used to convert
a. Direct current to Alternating current
b. Alternating current to Direct current
c. high voltage to low voltage
d. low voltage to high voltage
ANSWER :
b. Alternating current to Direct current
39. out of the following, which is not emitted by radioactive substance?
a. Electrons
b. Electromagnetic radiations
c. Alpha particles
d. Neutrons
ANSWER :
d. Neutrons
40. Sound waves in air are
a. transverse
b. longitudinal
c. electromagnetic
d. polarised
ANSWER :
b. longitudinal
41. If the spinning speed of the earth is increased then the weight of the body at the equator
a. Increases
b. Decreases
c. Doubles
d. Does not change
ANSWER :
b. Decreases
42. When the light is passed through a prism, the color which deviates least is
a. Red
b. Green
c. Violet
d. Blue
ANSWER :
a. Red
43. Which of the following is capillary not the reason only?
a. Rising of water from the roots of the plant to its foliage
b. Blotting of ink
c. Rising of underground water
d. The spread of water drop on a cotton cloth
ANSWER :
d. The spread of water drop on a cotton cloth
44. The focal length of the convex lens is
a. The same for all the colors
b. Shorter for blue light than for red
c. Shorter for red light than for blue
d. Maximum for yellow light
ANSWER :
b. Shorter for blue light than for red
45. The scent sprayer is based on
a. Carle’s law
b. Boyle’s law
c. Archimede’s principle
d. Bernoulli’s thereon
ANSWER :
d. Bernoulli’s thereon
46. Magnetism at the center of a bar magnet is
a. minimum
b. maximum
c. zero
d. minimum or maximum
ANSWER :
c. zero
47. It is more difficult to walk on a sandy road than on a concrete road because
a. sand is soft and concrete is hard
b. the friction between sand and feet is less than that between concrete and feet
c. the friction between sand and feet is more than that between concrete and feet
d. the sand is grainy but concrete is smooth
ANSWER :
b. the friction between sand and feet is less than that between concrete and feet
48. Find the maximum velocity for the overturn of a car moving on a circular track of radius 100 m. The coefficient of friction between the road and tire is 0.2
a. 0.14 m/s
b. 140 m/s
c. 1.4 km/s
d. 14 m/s
ANSWER :
d. 14 m/s
49. Of the following properties of a wave, the one that is independent of the other is its
a. amplitude
b. velocity
c. wavelength
d. frequency
ANSWER :
a. amplitude
50. Lux is the SI unit of
a. intensity of illumination
b. luminous efficiency
c. luminous flux
d. luminous intensity
ANSWER :
a. intensity of illumination
Explanation:
The SI unit of intensity of illumination (illuminance) is the lux. An illuminance of 1.0 lux is produced by 1.0 lumen of light shining on an area of 1.0 m^2.
PHYSICS Objective Questions pdf free download::
51. In which of the following cases lies the broadcast band of FM?
a. UHF
b. VHF
c. SHF
d. HF
ANSWER :
c. SHF
52. In the electric supply lines in India, which parameter is kept constant?
a. Current
b. Power
c. Voltage
d. Frequency
ANSWER :
d. Frequency
53. Which type of pen uses capillary action in addition to gravity for the flow of ink?
a. Fountain pen
b. Ballpoint pen
c. Gel pen
d. Both ballpoint and gel pens
ANSWER :
a. Fountain pen
54. Which waves are used in sonography?
a. Microwaves
b. Soundwaves
c. Infrared waves
d. Ultrasonic waves
ANSWER :
d. Ultrasonic waves
55. Which one of the following pairs of rays is electromagnetic in nature?
a. Alpha rays and X-rays
b. Alpha rays and cosmic rays
c. Infrared rays and beta rays
d. Infrared rays and X-rays
ANSWER :
d. Infrared rays and X-rays
56. On a rainy day, small oil films on water show brilliant colors. This is due to
a. dispersion
b. interference
c. diffraction
d. polarization
ANSWER :
b. interference
57. Point A is at a lower electrical potential than point b. An electron between them on the line joining them will
a. move towards A
b. move towards B
c. move at right angles to the line joining A and B
d. remain at rest
ANSWER :
b. move towards B
58. Materials for rain-proof coats and tents owe their water-proof properties to
a. surface tension
b. viscosity
c. specific gravity
d. elasticity
ANSWER :
a. surface tension
59. RADAR is used for
a. locating submerged submarines
b. receiving signals in a radio receiver
c. locating geostationary satellites
d. detecting and locating the position of objects such as airplanes
ANSWER :
d. detecting and locating the position of objects such as airplanes
60. Sound of frequency below 20 Hz is called
a. audio sounds
b. infrasonic
c. ultrasonic
d. supersonics
ANSWER :
b. infrasonic
61. What enables us to write on the blackboard with chalk?
a. Gravity
b. Cohesion
c. Adhesion
d. Viscosity
ANSWER :
c. Adhesion
62. You placed a car in an open parking area on a summer day. After a few hours, you noticed that the heat is trapped inside the car. This phenomenon is known as
a. Ozone depletion
b. Greenhouse effect
c. Solar effect
d. Cosmic ray impingement
ANSWER :
b. Greenhouse effect
63. Hair of a shaving brush clings together when the brush is removed from water due to
a. Viscosity
b. Elasticity
c. Friction
d. Surface tension
ANSWER :
d. Surface tension
64. SONAR is mostly used by
a. Doctor
b. Engineers
c. Astronauts
d. Navigators
ANSWER :
d. Navigators
65. Ball bearings are used in bicycles, cars, etc., because
of a. The actual area of a contract between the wheel and axle is increased
b. The effective area of a contract between the wheel and axle increased
c. The effective area of contact between the wheel and axle is reduced
d. None of the above statements is correct
ANSWER :
c. The effective area of contact between the wheel and axle is reduced.
66. On a clean glass plate, a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because
a. mercury is a metal
b. the density of mercury is greater than that of water
c. the cohesion of mercury is greater than its adhesion with glass
d. the cohesion of water is greater than its adhesion with glass
ANSWER :
c. the cohesion of mercury is greater than its adhesion with glass
67. Suitable impurities are added to a semiconductor depending on its use. This is done in order to
a. increase its life
b. enable it to withstand higher voltages
c. increase its electrical conductivity
d. increase its electrical resistivity
ANSWER :
c. increase its electrical conductivity
68. Stars twinkle because
a. the intensity of light emitted by them changes with time
b. the distance of the stars from the earth changes with time
c. the refractive index of the different layers of the earth’s atmosphere changes continuously, consequently the position of the image of a start changes with time
d. the light from the star is scattered by the dust particles and air molecules in the earth’s atmosphere
ANSWER :
c. the refractive index of the different layers of the earth’s atmosphere changes continuously, consequently the position of the image of a start changes with time
69. It takes much longer to cook food in the hills than in the plains because
a. in the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100oC causing an increase in cooking time
b. due to low atmospheric pressure on the hills, the water boils at a temperature higher than 100oC and therefore water takes longer to boil
c. in the hills the atmospheric density is low and therefore a lot of heat is lost to the atmosphere
d. in the hills the humidity is high and therefore a lot of heat is absorbed by the atmosphere leaving very little heat for cooking
ANSWER :
a. in the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100oC causing an increase in cooking time
70. Moment of inertia is
a. vector
b. scalar
c. phasor
d. tensor
ANSWER :
d. tensor
71. Of the following natural phenomena, tell which one known in Sanskrit as ‘deer’s thirst’?
a. Rainbow
b. Earthshine
c. Halo
d. Mirage
ANSWER :
d. Mirage
72. Inside an airplane, flying at a high altitude,
a. the pressure is the same as that outside
b. normal atmospheric pressure is maintained by the use of air pumps
c. the pressure inside is less than the pressure outside
d. normal humidity and partial vacuum are maintained
ANSWER :
b. normal atmospheric pressure is maintained by the use of air pumps
73. Sound travels with a different speed in media. In what order does the velocity of sound increase in these media?
a. Water, iron and air
b. Iron, air and water
c. Air, water and iron
d. Iron, water, and air
ANSWER :
c. Air, water, and iron
74. One thousand microns is equal to
a. 10-3m
b. 10-6m
c. 10-9m
d. 10-12m
ANSWER :
a. 10-3m
75. Sound travels at the fastest speed in
a. steel
b. water
c. air
d. vacuum
ANSWER :
a. steel
76. oil raise up the wick in a lamp. The principle involves
a. the diffusion of oil through the wick
b. the liquid state of oil
c. capillary action phenomenon
d. volatility of oil
ANSWER :
c. capillary action phenomenon
77. Superconductors are substances which
a. conduct electricity at low-temperature
b. offer high resistance to the flow of current
c. offer no resistance to the flow of electricity
d. conduct electricity at high temperatures
ANSWER :
c. offer no resistance to the flow of electricity
78. Light travels at the fastest speed in
a. glass
b. water
c. hydrogen
d. vacuum
ANSWER :
d. vacuum
79. Railway tracks are banked on curves
a. the necessary centrifugal force may be obtained from the horizontal component weight of the train
b. to avoid frictional force between the tracks and wheels
c. necessary centripetal force may be obtained from the horizontal component of the weight of the train
d. the train may not fly off in the opposite direction
ANSWER :
c. necessary centripetal force may be obtained from the horizontal component of the weight of the train
80. On a cold day when the room temperature is 15oC, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15oC because
a. metals have higher thermal capacity than plastics
b. plastics have a lower density than metals
c. metals are a good conductor of heat
d. plastics have a higher thermal conductivity than metals
ANSWER :
c. metals are a good conductor of heat
81. The sound produced at a point is heard by a person after 5 seconds, while the same sound is heard by another person after 6 seconds. If the speed of sound is 300 m/s, what could be the maximum and minimum distances between the two persons?
a. 1.8 km, 0.15 km
b. 2.2 km, 0.20 km
c. 2.8 km, 0.25 km
d. 3.3 km, 0.30 km
ANSWER :
d. 3.3 km, 0.30 km
82. The intensity of sound at a point is ____ its distance from the source.
a. directly proportional to
b. inversely proportional to
c. directly proportional to the square of
d. inversely proportional to the square of
ANSWER :
d. inversely proportional to the square of
83. Of the four locations mentioned below the highest inside temperature will be attained in the pressure cooker operated with the pressure valve open
a. at sea level
b. at the top of Mt. Everest
c. at a place in a valley below sea level
d. in an airplane flying at a height of 10,000 m with inside pressure maintained at the sea level
ANSWER :
c. at a place in a valley below sea level
84. Radio telescopes are better than optical telescopes because
a. they can detect faint galaxies which no optical telescope can
b. they can work even in cloudy conditions
c. they can work during the day and night
d. All of the above
ANSWER :
d. All of the above
85. Light Emitting Diodes (LED) is used in fancy electronic devices such as toys emit
a. X-rays
b. ultraviolet light
c. visible light
d. radio waves
ANSWER :
c. visible light
86. Out of the following pairs, which one does not have an identical dimension?
a. Moment of inertia and moment of a force
b. Work and Torque
c. Angular momentum and Planck’s constant
d. Impulse and Momentum
ANSWER :
a. Moment of inertia and moment of a force
87. Mercury is commonly used as a thermometric fluid rather than water because
a. specific heat of mercury is less than water
b. specific heat of mercury is more than water
c. mercury has greater visibility than water
d. the density of mercury is more than the water
ANSWER :
c. mercury has greater visibility than water
88. Optical fiber works on the
a. principle of refraction
b. total internal reflection
c. scattering
d. interference
ANSWER :
b. total internal reflection
89. Light from the star, Alpha Centauri, which is nearest to the earth after the sun, reaches the earth in
a. 4.2 seconds
b. 42 seconds
c. 4.2 years
d. 42 years
ANSWER :
c. 4.2 years
90. Supersonic plane fly with the speed
a. less than the speed of sound
b. of sound
c. greater than the speed of sound
d. of light
ANSWER :
c. greater than the speed of sound
91. Mach number is used in connection with the speed of
a. sound
b. aircraft
c. spacecraft
d. ships
ANSWER :
b. aircraft
92. On a stationary sailboat, the air is blown from a fan attached to the boat. The boat
a. moves in the opposite direction in which the air is blown
b. does not move
c. moves in the same direction in which air blows
d. spins around
ANSWER :
b. does not move
93. Rainbow is due to
a. absorption of sunlight in minute water droplets
b. diffusion of sunlight through water droplets
c. the ionization of water deposits
d. refraction and reflection of sunlight by water droplets
ANSWER :
d. refraction and reflection of sunlight by water droplets
94. Stars which appear single to the naked eye but are double when seen through a telescope are
a. novas and supernovas
b. binaries
c. asteroids
d. quasars
ANSWER :
b. binaries
95. ML2T-2 is the dimensional formula for
a. moment of inertia
b. pressure
c. elasticity
d. couple acting on a body
ANSWER :
d. couple acting on a body
96. A solar eclipse will take place when
a. the sun is between the moon and the earth
b. the earth is between the moon and the sun
c. the moon is between the sun and the earth
d. the moon does not lie on the line joining the sun and the earth
ANSWER :
c. the moon is between the sun and the earth
97. Isotopes of an element contain
a. the same number of protons but a different number of neutrons
b. the same number of neutrons but a different number of protons
c. an equal number of protons and electrons
d. an equal number of nucleons
ANSWER :
a. the same number of protons but different number of neutrons
98. One watt-hour is equivalent to
a. 6.3 x 103 J
b. 6.3 x 10-7 J
c. 3.6 x 103 J
d. 3.6 x 10-3 J
ANSWER :
c. 3.6 x 103 J
99. Sir c.V. Raman was awarded Nobel Prize for his work connected with which of the following phenomenon of radiation?
a. Scattering
b. Diffraction
c. Interference
d. Polarization
ANSWER :
a. Scattering
100. In which of the following industries is mica as a raw material?
a. Cement
b. Glass and Pottery
c. Iron and Steel
d. Electrical
ANSWER :
d. Electrical
Physics Interview Questions::
1. What is Quantum Physics?
The understanding of the behavior of matter and energy at the molecular, nuclear, atomic and even microscopic levels is referred to as Quantum physics
2. What is Quantum entanglement?
Quantum entanglement is one of the central principles of quantum physics, which means multiple particles are linked together in a way that the measurement of one particle quantum state determines the possible quantum of the other particles
3. Define what is shearing stress?
Shearing stress is the ratio of the tangential force F to the area of the face BCGH over which it is applied. The ratio shearing stress is divided by shearing strain is the shear module or coefficient of rigidity, n
Shearing stress = const
Shearing strain
4. Define what is the speed of light in space?
In the space, light travels at a speed of 186,282 miles per second and sunlight take about 8 min and 19 sec to reach the surface of the earth.
5. What are the properties of the fourth matter Plasma?
After Solid, liquid and gas there is one more matter that exists known as Plasma. Properties of Plasma are
- Plasma has neither a definite shape nor a definite volume
- Plasma often seen in ionized gases, and heating produces it and ionizing a gas
- Free electrical charges which are not bound to atoms or ions can cause the plasma to be electrically conductive
- Some of the examples of plasma are lightning, stars, inside fluorescent lights and neon signs
6. Define what is Thermal Conductivity?
The property of the material that relates to its ability to conduct heat is referred to as Thermal Conductivity.
7. Define what is Parallax and Distance Measurement?
To measure the distance to nearby stars, astronomers use an effect called Parallax. Parallax is the apparent displacement of an object because of a change in observer’s point of view, for instance, when we look at an object with one eye shut and then doing the same with another eye, there is a difference in the position of the object this is known as Parallax.
To measure the star position astronomer uses this technique. Once the star position is located after six months they will again calculate the apparent change in position.
8. Define what is the unit to measure the heat resistance?
Ohm is the unit to measure the heat resistance.
9. What is the instrument used to know the scattering of light by particles suspended in a liquid?
Nephelometer is the instrument used to measure the scattering of light by particles suspended in a liquid
10. Define what is dyne?
Dyne is a unit of force or also referred to as C-G-S (centimeter – gram –-second). It means that when a force is applied to a mass of 1 gram, it gives an acceleration of 1 centimeter per second.
11. Define what is Wave-Particle duality?
When matter and light exhibit properties of both waves and particles, it is referred to as Wave-Particle Duality. For instance, Light can behave like a wave when it shines through narrow slits while, when exposed to some metal surface it will spray electrons acting like a particle. So under different conditions, it will act.
12. Define what is Quantum tunneling?
Quantum tunneling is the process where the particle passes through an obstruction or barrier to reach at another end. It is referred to as tunneling as the particle as “dug” out the way through the potential barrier.
13. Define what is the Uncertainty principle?
Uncertainty principle tells that the momentum and position of a particle cannot be measured precisely.
14. Define what is dark matter?
Dark matter is an invisible matter in the space that can hold the stars into the galaxy. They have no effect of electromagnetic force on it, which means it does absorb, reflect or emit light that makes them practically invisible.
15. Define what is a photon under the photon theory of light?
A discrete bundle of electromagnetic light or energy, which always remains in motion is referred to as a photon.
16. Mention what are the properties of Photon?
- It moves at a constant velocity
- It has zero mass and rests energy
- When exposed (absorbed/emitted) to radiation it can be destroyed or created
- With the electron and another particle, it will show particle like interaction
- It carries energy and momentum
17. Define what is Pascal law?
A Pascal law states that when you apply force at one point on liquid it will transmit equal force from one location to another within the liquid.
18. Define what is Neutrino?
Neutrino is a small, tiny elementary particle which carries no electrical charge which means it is not affected by electromagnetic forces, and travels almost the speed of light and passes through ordinary matter without making any interaction.
19. Mention the factors on which the velocity of sound depends?
The velocity of sound depends on the velocity and density of the medium on which it travels. It varies directly as the square root of elasticity and inversely as the square root of the density.
20. Define the term “Convection”?
Convection is the process of transferring heat by movement of a heated fluid such as water or air. In this process, the heated fluid expands, and gravity pulls the denser masses under them thus forcing them into motion. One good example is a draft of lamps and stoves.
21. Define the term angular acceleration?
Angular acceleration is the rate of change of angular velocity or speed of a body moving along a circular path.