Most important Physics Solved MCQs.

VERY IMPORTANT PHYSICS SOLVED MCQs

1.The unit of Electric intensity other than NC^-1 is:
(a) N/V
(b) V/C
(c) V/m✔
(d) V/A

2. The electric field created by positive charge is:
(a)radially outward✔
(b) circular
(c) zero
(d) radially inward

3. Special organ called ampullae of lorenzini that are very sensitive to electric field are found in:
(a) sharks✔
(b) dogs
(c) cats
(d) bats

4. If a charged body is moved against the electric field, it will gain:
(a) electrical potential energy✔
(b) mechanical energy
(c) K.E
(d) P.E

5. The electric field lines are closer where the field is:
(a) variable
(b) uniform
(C) weak
(d) Strong✔

6. The lines which provide information about the electric force exerted on charged particles are
(a) curved lines
(b) tangent lines
(c) electric field lines✔
(d) magnetic field lines

7. A charge of 1μc experience a force of 10-N at a point then the electric intensity at that
point is:
(a) 1NC^-1✔
(b) 10^-12 NC^-1
(c) 10^-6 NC^1
(d) 10^6 NC^1

8. Two equal and opposite point charges separated by a distance 2m. The electric potential at the midway between them is:
(a) constant
(b) low
(c) high
(d) zero✔

9. Absolute potential difference due to point change of 1C at a distance of 1m is given by:
(a)9×10^9V✔
(b)9×10^8V
(c)9×10^7v
(d)9×10^6v

10. A particle having 2e charge falls through a potential difference by 5v. Energy acquired by
it is:
(a) 10 eV✔
(b) 0.4 eV
(c) 20 eV
(d) 2.5 eV

11. Farad is the unit of:
(a) capacitance✔
(b) electric flux
(c) current
(d) charge

12. The unit of electric charge is:
(a) Weber
(b) Coulomb✔
(c) Henry
(d) Volt

13. The absolute electric potential at a point distant 20cm from a charge of 2uC is:
(a)9 x 10^2 v
(b)9 x 10^3 v
(c)9 x 10^4 v✔
(d)9 x 10^5 v

14. The relation △v/△r represents:
(a) potential difference
(b) electric intensity ✔
(c) electrical flux
(d) Gauss’s law

15. An ECG records……..between points on human skin.
(a) electric flux
(b) current
(c) voltage✔
(d) all of these

16. ERG stands for:
(a) electric radiation graph
(b) electric ratino graphy✔
(c) energy radio graph
(d) electro radio graphy

17. The negative of the potential gradient is:
(a) electromotive force
(b) electrical field intensity✔
(c) electrostatic force
(d) charge in potential

18. 1 NC-1 =
(a) 1 Vm^1
(b) 1vm^-1✔
(c) 1V 1m-1
(d) 1 vim

19. A charge of 10^-10 c between two parallel plates 1 cm apart experience of a foce of 10
(a) 104 v
(b) 103 v✔
(c) 102 v
(d) 10 V

20. Work done in bringing a unit positive charge from infinity to that point in an electric
is called:
(a) absolute potential ✔
(b) capacitance
(c) resistance
(d) potential difference

21. If charged body is moved against the electric field, it will gain:
(a)electrical potential energy✔
(b)mechanical energy
(C)K.E
(d)P.E

22. Color code for yellow color is:
(a)5
(b)4✔
(c)3
(d)2

23. If fourth band is missing on resistance, its tolerance is:
(a)±20%✔
(b)±15%
(C)±10%
(d)±25%

24. Which of the following is not accurate measuring device?
(a)voltmeter✔
(b)potentiometer
(c)CRO
(d)digital multimeter

25. In colour code for resistance orange colour represents:
(a)3✔
(b)2
(c)1
(d)0

26. The colour of strips on a carbon resistor from extreme left is yellow, black and red respectively. Its resistance is:
(a) 40kΩ
(b) 40Ω
(c) 400Ω
(d) 4kΩ✔

27. The numerical value of green colour in colour code carbon resistor is:
(a)8
(b)5✔
(c)3
(d)0

28. The numerical value of violet colour in colour code resistors is:
(a) 07✔
(b) 05
(c) 06
(d) 0

29. If fourth band on a carbon resistor is of silver colour then its tolerance is:
(a)± 1%
(b)± 5%
(c)± 10%✔
(d)± 20%

30. The colour code for carbon resistance usually consists of:
(a)7 bands
(b)2 bands
(c)4 bands✔
(d)3 bands

31. Resistance tolerance for gold colour is:
(a)5%✔
(b)20%
(c)30%
(d)50%

32. The numerical value of black colour in carbon resistors is:
(a)0✔
(b)1
(c)2
(d)3

33. Silver band shows the tolerance of:
(a)±5%
(b)±10%✔
(c)±20%
(d)±25%

34. In carbon resistors, the value of blue colour is:
(a)6✔
(b)7
(c)8
(d)9

35. What is the resistance of a carbon resistor which has band brown black brown?
(a) 1.0 ohm
(b) 10 ohm
(c) 100 ohm✔
(d) 1000 ohm

36. Kirchoff’s first rule is based on conservation of:
(a) Mass
(b) Charge✔
(c) Voltage
(d) Energy

37. Kirchoff’s first rule is the manifestation of law of conservation of:
(a) charge✔
(b) energy
(c) momentum
(d) mass

38. Kirchhoff’s voltage rule is a way of stating conservation of:
(a) angular
(b) charge
(c) momentum
(d) energy✔

39. Potentiometer can be used to find:
(a) internal resistance of the cell
(b) comparison of two low resistances
(c) comparison of emf of two cells
(d) all of these✔

40. The relation for potentiometer is given:
(a) E1/E2=ℓ1/ℓ2✔
(b) E2/E1=ℓ2/ℓ1
(c) E3/E4=ℓ3/ℓ4
(d) none of these

41. Which one of the following particles moving in the magnetic field cannot be deflected:
(a) neutron✔
(b) electron
(c) B-particle
(d) a-particle

42. Force on moving charge in a magnetic field, is given by:
(a) F = q(B – V)
(b) F = q(B + V)
(C) F = q(V x B)✔
(d) F = q(B x V)

43. The charges moving perpendicular to magnetic field experience force:
(a) infinity
(b) zero
(c) minimum
(d) maximum✔

44. When a charge is projected perpendicular to a uniform magnetic field, its path:
(a) circular✔
(b) ellipse
(c) helix
(d) spiral

45. An electron enters the magnetic field at right angle from left, B is into paper. The electron
will be deflected:
(a) towards left
(b) downward ✔
(c) towards right
(d) upward

46. If Fi and Fy are forces acting on a -particle and electron respectively, when moving perpendicular to the magnetic field then:
(a)F1 = 4F2
(b)F1 < F2
(C)F1 > F2✔
(d)F1 = F2

47. Filament in C.R.O:
(a) perfect insulators
(b) perfect conductors
(c) insulators
(d) conductors✔

48. Cathode Ray Oscilloscope works by deflecting beam of:
(a) positrons
(b) protons
(C) electrons ✔
(d) neutrons

49. The velocity of an oscillating charge as it moves to and fro along the wire is:
(a)infinite
(b)constant
(C)changing ✔
(d)zero

50. The CRO is used for:
(a) displaying wave form of given voltage ✔
(b) converting A.C into D.C
(c) displaying wave form of frequency
(d) displaying wave form of given vibration

51. In CRO, the output wave form of time base generator is:
(a) saw-tooth✔
(b) sinusoidal
(c) square
(d) circular

52. The brightness of the input on CRO screen is controlled by:
(a) plato
(b) grid✔
(c) anode
(d) cathode

53. The function of three anodes in a CRO is:
(a) to focus the electrons
(b) accelerate and focus the electrons✔
(c) to control the brightness of spot on screen
(d)to accelerate eletrons only

54. If an electron of charge ‘e’ is accelerated through a potential difference v, it will acquire energy:
(a) Ve^2
(b) E/V
(c) V/2
(d) Ve✔

55. The particle that produce the display on a cathode ray oscilloscope (CRP) are obtained by heating a metal filament. What are these particles?
(a) α-particles
(b) neutrons
(c) protons
(d) electrons✔

56. Lenz’s law is in accordance with the law of conservation of:
(a) energy✔
(b) charge
(c) angular momentum
(d) momentum

57. Lenz’s law deals with:
(a) resistance
(b) direction of induced current✔
(c) direction of emf
(d) magnitude of emf

58. Lenz’s law is a consequence of the law of conversation of:
(a) momentum
(b) energy✔
(c) current
(d) charge

59. “The direction of induced current is always so as to oppose the change which causes the current”. It is the statement of………
(a) Lenz’s law✔
(b) Faraday’s law
(c) Guass’s law
(d) Ampere’s law

60. In a three phase AC generator the phase difference between each pair of coil is:
(a)120°
(b)90°✔
(c)60°
(d)45°

61. In three phase voltage across any two lines is about:
(a)430 V
(b)400 V
(c)230 V
(d)220 V✔

62. Three phase AC supply machine has:
(a)6 terminal✔
(b)4 terminal
(c)2 terminal
(d)no terminal

63. The number of coils used in three phase AC generated are:
(a)4
(b)3✔
(c)2
(d)1

64. The voltage across each of lines connected to terminals A,B and C of machine and the neutral line in three phase AC supply is:
(a) 440 V
(b) 400 V
(c) 230 V
(d) 120 V✔

65. The device used for converting A.C into D.C is called:
(a) oscillator
(b) amplifier
(c) detector
(d) rectifier (or diode)✔

66. In full wave rectification number of diodes required are equal to:
(a)1
(b)3
(c)4✔
(d)5

67. Pulsating DC can be made smooth by using a circuit known as:
(a) accepter
(b) tank
(c) filter✔
(d) all of these

68. The device used for rectification is called:
(a)wheat stone bridge
(b)thermistor
(C)rectifier✔
(d)transformer

69.Process of converting alternative current into direct current is called:
(a) ampllification ✔
(b) rectificaiton
(c) modulation
(d) polarization

70. A diode can be used as:
(a) transistor
(b) oscillator
(c) rectifier✔
(d) amplifier

71. The type of rectifications are:
(a)5
(b)4
(c)3
(d)2✔

72. For rectification we use:
(a) generator
(b) choke
(c) diode✔
(d) transformer

73. The process due to which current flows only during alternate half cycle is known as:
(a)saturation
(b)full wave rectification
(c)half wave rectification✔
(d)amplication

74. Minimum number of semi-conductors diodes required for full rectification are: IMCA
(a)4✔
(b)3
(c)2
(d)1

75. If the output voltage is not smooth but pulsating, then it can be made smooth by us circuit known as:
(a)transistor
(b)LED
(c)gate
(d)filter✔

76. The output voltage of a rectifier is:
(a) alternating
(b) perfectly direct
(c) pulsating✔
(d) smooth

77. The inverse phenomena to x-rays emission is:
(a) Photoelectric effect ✔
(b) Interference
(c) Polarization
(d) Diffraction

78. For Holography we use:
(a) B-rays
(b) y – rays
(c) Laser✔
(d) X-rays

79. Life time of excited state (meta stable) is:
(a) 10-85
(b) 10-55
(c) 10-35✔
(d) 10-25

80. Helium-Neon laser discharge tube contains neon:
(a) 85%
(b) 25%
(c) 15%✔
(d) 82%

81. A finally focused beam of laser used to destroy:
(a) Living cells
(b) Pre-cancerous cells
(c) Cancerous cells
(d) Both B and C ✔

82. The population inversion is, in which:
(a) Some electrons are in ground state
(b) Majority of electrons are in excited state✔
(c) Some electrons are in excited state
(d) All electrons are in excited state

83. The most common type of lasers used in physics laboratories are:
(a) helium neon laser ✔
(b) argon laser
(c) neon laser
(d) none of these

84. The SI unit of Rydberg constant is:
(a) JS
(b) NS
(c) m^-1✔
(d) m^-2

85. In Wilson cloud chamber we used:
(a) water vapors
(b) bromine gas
(c) neon gas
(d) alcohol vapors✔

86. Which one is a better shield against Y -rays:
(a) water
(b) aluminum
(c) lead✔
(d) wood

87. A proton consists of quarks which are:
(a) all up
(b) all down
(c) 2 up, 1 down✔
(d) 1 up, 2 down

88. Absorbed dose ‘D’ is defined as:
(a) E/M✔
(b) C/M
(c) E/C
(d) M/E

89. A particle is made up of two up quards and one down quark is:
(a) Lepton
(b) Boson
(c) Neutron
(d) Proton✔

90. Three up quarks combine to form a new particle, the charge on this particle is:
(a) 4e
(b) 3e
(c) 2e✔
(d) le

91. Which of the following belongs to ‘hadrons’ group:
(a) neutrinos
(b) muons
(c) electrons
(d) proton✔

92. Curie is large unit which equals to disintegration per second.
(a)3 x 10^6
(b)3.7 x 10^8
(c)3 x 10^8
(d)3.7 x 10^10✔

93. Particles that experience the strong nuclear force:
(a) quarks
(b) photons
(c) leptons
(d) hadrons✔

94. The particles equal in mass or greater than protons are called:
(a) mouns
(b) mesons
(C) baryons✔
(d) leptons

95. A pair of quark and anti-quark make a:
(a)meson✔
(b)baryon
(c)lepton
(d)harden

96. Every particle has corresponding antiparticle with:
(a) same mass
(b) same mass and opposite charge✔
(c) different mass
(d) opposite charge

97. The number of types of quarks is:
(a) 3
(b) 4
(c) 5
(d) 6✔

98. Which of the followings are not hadrons?
(a) neutrons
(b) protons
(c) mesons
(d) muons✔

99. Which group belongs to hadrons?
(a) protons and neutrons✔
(b) muons and neutrons
(c) positrons and electrons
(d) photons and electrons

100. The most common type of lasers used in physics laboratories are
(a) helium neon laser✔
(b) argon laser
(c) neon laser
(d) none