Class 12 Physics Ch-4 Magnetic Effects of Electric Current MCQs Exam 2027

Part A: Electrostatics

1. The expression for the capacitance ($C$) of a conductor is:

(A) $Q/V$

(B) $V/Q$

(C) $Q \cdot V$

(D) $Q^2 \cdot V$

2. How many electrons are there in 1 Coulomb of charge?

(A) $6.25 \times 10^{18}$

(B) $1.6 \times 10^{-19}$

(C) $6.25 \times 10^{19}$

(D) $9 \times 10^9$

3. The S.I. unit of Electric Dipole Moment is:

(A) $C \cdot m$

(B) $C/m$

(C) $C \cdot m^2$

(D) $N/C$

4. The static electric field is:

(A) Conservative

(B) Non-conservative

(C) Somewhere conservative, somewhere non-conservative

(D) None of these

5. Farad (F) is the unit of:

(A) Current

(B) Resistance

(C) Capacitance

(D) Potential

6. A dipole is placed inside a closed surface. The total electric flux will be:

(A) Infinite

(B) Zero

(C) $q/\epsilon_0$

(D) None of these

7. The dimensional formula of electrical capacitance is:

(A) $[M^{-1}L^{-2}T^4I^2]$

(B) $[M^1L^2T^{-4}I^{-2}]$

(C) $[M^0L^0T^0I^0]$

(D) $[M^{-1}L^{-2}T^3I^1]$

8. The value of electric potential ($V$) in the axial position is:

(A) $\frac{1}{4\pi\epsilon_0} \cdot \frac{p \cos \theta}{r^2}$

(B) $\frac{1}{4\pi\epsilon_0} \cdot \frac{p}{r^2}$

(C) Zero

(D) None of these

9. In the equatorial position, the electric potential is:

(A) Zero

(B) Infinite

(C) $9 \times 10^9$

(D) $p/r^2$

10. The surface density of charge ($\sigma$) is:

(A) $Q/A$

(B) $Q \cdot A$

(C) $A/Q$

(D) $Q/L$

11. The dielectric constant of water is:

(A) 80

(B) 60

(C) 1

(D) 18

12. The value of $\epsilon_r$ in air is:

(A) Zero

(B) Infinite

(C) 1

(D) 9

13. The relation between electric field ($E$) and potential ($V$) is:

(A) $E = -dV/dx$

(B) $E = dV/dx$

(C) $V = dE/dx$

(D) $E = V \cdot x$

14. Charge on a capacitor of capacity 10 $\mu F$ charged to 5V will be:

(A) $50\ C$

(B) $50 \times 10^{-6}\ C$

(C) $2 \times 10^{-6}\ C$

(D) $5\ C$

15. The unit of electric field intensity is:

(A) $N/C$

(B) $V/m$

(C) Both (A) and (B)

(D) None of these

Part B: Current Electricity

16. Which quantity remains the same in the parallel combination of resistors?

(A) Potential difference

(B) Current

(C) Resistance

(D) None of these

17. The absorbed electrical energy is:

(A) Proportional to potential difference

(B) Inversely proportional to potential difference

(C) Proportional to the square of the potential difference

(D) None of these

18. A Wheatstone bridge is used to measure:

(A) High resistance

(B) Low resistance

(C) Both high and low resistance

(D) Potential difference

19. The power (P) of an electric circuit is:

(A) $V \cdot R$

(B) $V^2 \cdot R$

(C) $V^2/R$

(D) $V \cdot I^2$

20. Electron-volt (eV) is the measure of:

(A) Charge

(B) Potential difference

(C) Current

(D) Energy

21. Kirchhoff’s second law (Loop Law) is based on:

(A) Conservation of charge

(B) Conservation of energy

(C) Conservation of momentum

(D) None of these

22. The electrical resistance of a healthy human body (dry) is:

(A) 50,000 $\Omega$

(B) 10,000 $\Omega$

(C) 1,000 $\Omega$

(D) 10 $\Omega$

23. Which of the following is the best conductor of electricity?

(A) Silver

(B) Copper

(C) Gold

(D) Iron

24. What is measured by a Voltmeter?

(A) Current

(B) Potential Difference

(C) Resistance

(D) Charge

25. With an increase in temperature, the resistance of a semiconductor:

(A) Increases

(B) Decreases

(C) Remains unchanged

(D) Becomes zero

Part C: Magnetic Effect of Current & Magnetism

26. The resistance of an Ammeter is $G$ and its range is $I$. To increase the range to $nI$, the parallel resistance required is:

(A) $G/(n-1)$

(B) $G/n$

(C) $G(n-1)$

(D) $nG$

27. The value of the Dip angle at the magnetic equator is:

(A) $0^\circ$

(B) $45^\circ$

(C) $90^\circ$

(D) $180^\circ$

28. The expression for force on a charge ($q$) moving with velocity $\vec{v}$ in magnetic field $\vec{B}$ is:

(A) $\vec{F}_m = q(\vec{v} \times \vec{B})$

(B) $\vec{F}_m = q(\vec{B} \times \vec{v})$

(C) $\vec{F}_m = \frac{q}{(\vec{v} \times \vec{B})}$

(D) $\vec{F}_m = \frac{1}{q}(\vec{v} \times \vec{B})$

29. A Cyclotron is not suitable for accelerating which particle:

(A) Proton

(B) Electron

(C) Deuteron

(D) $\alpha$-particle

30. One Tesla (1 T) is equal to:

(A) $1\text{ Wb/m}^2$

(B) $10^8\text{ Wb/m}^2$

(C) $10^{-4}\text{ Wb/m}^2$

(D) $10^4\text{ Wb/m}^2$

31. The energy density of magnetic field $\vec{B}$ is:

(A) $\frac{B^2}{\mu_0}$

(B) $\frac{B^2}{2\mu_0}$

(C) $\frac{B^2}{3\mu_0}$

(D) $\frac{B^2}{4\mu_0}$

32. The magnetic field at the center of a circular current-carrying coil is:

(A) In the plane of the coil

(B) Perpendicular to the plane of the coil

(C) At $45^\circ$ to the plane

(D) At $180^\circ$ to the plane

33. The value of permeability of free space ($\mu_0$) is:

(A) $4\pi \times 10^{-7} \text{ H/m}$

(B) $4\pi \times 10^{7} \text{ H/m}$

(C) $4\pi \times 10^{-11} \text{ H/m}$

(D) $4\pi \times 10^{11} \text{ H/m}$

34. Who discovered the magnetic effect of electric current:

(A) Fleming

(B) Ampere

(C) Oersted

(D) Faraday

35. The S.I. unit of magnetic flux is:

(A) Tesla

(B) Henry

(C) Weber

(D) Joule-second

36. The value of the Dip angle at the magnetic poles is:

(A) $0^\circ$

(B) $45^\circ$

(C) $90^\circ$

(D) $180^\circ$

37. The resistance of an ideal voltmeter is:

(A) Zero

(B) Very low

(C) Very high

(D) Infinite

38. The rule to find the direction of Lorentz force is:

(A) Fleming’s Left-hand rule

(B) Fleming’s Right-hand rule

(C) Ampere’s Swimming rule

(D) Maxwell’s Screw rule

39. The approximate value of magnetic field $\vec{B}$ on Earth’s surface is:

(A) $10^{-1}$ Tesla

(B) $10^{-2}$ Tesla

(C) $10^{-3}$ Tesla

(D) $10^{-5}$ Tesla

40. If only $1\%$ of the main current passes through a galvanometer, the shunt value should be:

(A) $G/99$

(B) $G/100$

(C) $G/101$

(D) $99G$

41. The nature of an electron beam moving with the same velocity in the same direction will be:

(A) Converging

(B) Diverging

(C) Parallel

(D) None of these

42. The magnetic dipole moment ($M$) of a current-carrying coil is:

(A) $M = NIA$

(B) $M = N/IA$

(C) $M = NI/A$

(D) $M = A/NI$

43. A charge moving with uniform velocity produces:

(A) Electric field only

(B) Magnetic field only

(C) Electromagnetic field

(D) None of these

44. Increasing the number of turns in a moving coil galvanometer increases its:

(A) Sensitivity

(B) Resistance

(C) Range

(D) None of these

45. The torque ($\vec{\tau}$) experienced by a magnetic dipole $\vec{M}$ in field $\vec{B}$ is:

(A) $\vec{\tau} = \vec{M} \times \vec{B}$

(B) $\vec{\tau} = \vec{B} \times \vec{M}$

(C) $\vec{\tau} = \vec{M} \cdot \vec{B}$

(D) $\vec{\tau} = \frac{\vec{M}}{\vec{B}}$

46. A galvanometer is converted into a voltmeter by joining:

(A) High resistance in parallel

(B) High resistance in series

(C) Low resistance in series

(D) Low resistance in parallel

47. The formula for the magnitude of magnetic force on a moving charge is:

(A) $F = qvB$

(B) $F = qvB \sin \theta$

(C) $F = q/vB$

(D) $F = \frac{vB \sin \theta}{q}$

48. If the magnetic field is halved, the radius of the circular path of a charged particle becomes:

(A) Half

(B) Double

(C) Unchanged

(D) Four times

49. The sensitivity of a moving coil galvanometer can be increased by:

(A) Decreasing number of turns

(B) Increasing magnetic flux

(C) Decreasing the area

(D) Increasing the torsion constant

50. Intensity of magnetization ($H$) is equal to:

(A) $\frac{B_0}{\mu_0}$

(B) $\frac{\mu_0}{B_0}$

(C) $B_0 \mu_0$

(D) $\sqrt{B_0 \mu_0}$

51. A straight conductor carries 10 A current. Magnetic field at 2 cm distance is:

(A) $10^{-4}$ Tesla

(B) $2 \times 10^{-4}$ Tesla

(C) $10^{-5}$ Tesla

(D) $2 \times 10^{-5}$ Tesla

52. The direction of magnetic field inside a current-carrying solenoid is:

(A) Circular

(B) Parallel to the axis

(C) Perpendicular to the axis

(D) Irregular

53. To convert a galvanometer into an ammeter, we connect:

(A) Low resistance in parallel

(B) High resistance in series

(C) Low resistance in series

(D) High resistance in parallel

54. By using a shunt, the sensitivity of a galvanometer:

(A) Decreases

(B) Increases

(C) Remains same

(D) Becomes zero

55. The unit of $\sqrt{\frac{\mu_0}{\epsilon_0}}$ is:

(A) Newton/Ampere

(B) Ohm ($\Omega$)

(C) Weber

(D) Farad

56. The maximum velocity of a charged particle in a Cyclotron is:

(A) $v_{max} = \frac{qBR}{m}$

(B) $v_{max} = \frac{qB}{mR}$

(C) $v_{max} = \frac{mR}{qB}$

(D) $v_{max} = \frac{qR}{mB}$

57. Which quantity of a particle remains unchanged in a magnetic field?

(A) Velocity

(B) Speed only

(C) Kinetic energy only

(D) Both speed and kinetic energy

58. Two parallel conductors carrying current in the same direction:

(A) Attract each other

(B) Repel each other

(C) Apply no force

(D) None of these

59. The correct vector form of Biot-Savart Law is:

(A) $d\vec{B} = \frac{\mu_0 I(d\vec{l} \times \vec{r})}{4\pi r^2}$

(B) $d\vec{B} = \frac{\mu_0 I(d\vec{l})}{4\pi r^2}$

(C) $d\vec{B} = \frac{\mu_0 I(d\vec{l} \times \vec{r})}{4\pi r^3}$

(D) $d\vec{B} = \frac{\mu_0 I \vec{r}}{4\pi r^2}$

60. Dimensions of Magnetic Induction are:

(A) $[MT^{-2}I^{-1}]$

(B) $[MLT^{-2}I^0]$

(C) $[MI]$

(D) $[M^{-1}L^{-1}T^{-2}I]$

61. Relationship between geometric length ($L_g$) and magnetic length ($L_m$) of a magnet is:

(A) $L_m = \frac{5}{6} L_g$

(B) $L_m = \frac{6}{5} L_g$

(C) $L_m = L_g$

(D) $L_m = 2 L_g$

62. For Ferromagnetic substances, permeability ($\mu$) is:

(A) $\mu >> 1$

(B) $\mu < 1$

(C) $\mu = 1$

(D) $\mu = 0$

63. Nickel is:

(A) Diamagnetic

(B) Paramagnetic

(C) Ferromagnetic

(D) None of these

64. The angle between magnetic meridian and geographic meridian is called:

(A) Angle of Dip

(B) Declination

(C) Magnetic Induction

(D) None of these

65. On heating, a magnet’s magnetism:

(A) Increases

(B) Decreases

(C) Gets destroyed

(D) Remains unchanged

66. A wire of magnetic moment $M$ bent into a semi-circle will have new moment:

(A) $M$

(B) $\frac{M}{2\pi}$

(C) $\frac{M}{\pi}$

(D) $\frac{2M}{\pi}$

67. Resistance of an ideal ammeter is:

(A) Zero

(B) Very low

(C) Very high

(D) Infinite

68. The magnetic susceptibility ($\chi$) of paramagnetic substances is:

(A) Constant

(B) Zero

(C) Infinite

(D) Dependent on magnetic field

69. Unit of magnetic flux density is:

(A) Tesla

(B) Weber

(C) Henry

(D) Ohm

70. Above Curie Temperature, ferromagnetic materials become:

(A) Paramagnetic

(B) Diamagnetic

(C) Semiconductor

(D) Insulator

Part D: Electromagnetic Induction & Alternating Current

71. The unit of Inductance ($L$) is:

(A) Henry

(B) Ohm

(C) Weber

(D) Tesla

72. Self-inductance of a coil is a measure of:

(A) Electrical Inertia

(B) Electrical Friction

(C) Induced Current

(D) Induced Voltage

73. Dimensional formula of $L/R$ is:

(A) $[M^0L^0T^{-1}]$

(B) $[M^0L^0T]$

(C) $[MLT^{-1}]$

(D) $[M^0L^0T^0]$

74. The relation between $I_{rms}$ and peak current $I_0$ in A.C. is:

(A) $I_{rms} = I_0/2$

(B) $I_{rms} = I_0/\sqrt{2}$

(C) $I_{rms} = \sqrt{2} I_0$

(D) $I_{rms} = I_0$

75. The value of Inductive Reactance $X_L$ is:

(A) $\omega L$

(B) $1/\omega L$

(C) $\omega^2 L$

(D) $L/\omega$

76. Capacitive Reactance $X_C$ is:

(A) $1/\omega C$

(B) $\omega C$

(C) $\omega/C$

(D) $C/\omega$

77. In a Step-up transformer, which quantity increases?

(A) Current

(B) Voltage

(C) Power

(D) Frequency

78. The Core of a transformer is made of:

(A) Soft Iron

(B) Copper

(C) Aluminium

(D) Steel

79. The principle of working of a Dynamo is based on:

(A) Magnetic effect of current

(B) Electromagnetic Induction

(C) Induced Magnetism

(D) None of these

80. Impedance of L-R circuit is:

(A) $R + \omega L$

(B) $R^2 + \omega^2 L^2$

(C) $\sqrt{R^2 + \omega^2 L^2}$

(D) $R$

81. Unit of Mutual Induction is:

(A) Henry

(B) Weber

(C) Tesla

(D) Farad

82. In an A.C. circuit, power is consumed only in:

(A) Resistance

(B) Inductance

(C) Capacitance

(D) All of these

83. Power factor of a Choke Coil is approximately:

(A) 0

(B) 1

(C) 0.5

(D) Infinite

84. A Hot-wire ammeter measures the following value of A.C.:

(A) Peak value

(B) Average value

(C) Root-mean-square (rms) value

(D) None of these

85. Average value of A.C. over a full cycle is:

(A) $2I_0/\pi$

(B) $I_0/\sqrt{2}$

(C) Zero

(D) $I_0$

Part E: Optics

86. The S.I. unit of Power of a lens is:

(A) Joule

(B) Candela

(C) Dioptre

(D) Watt

87. Critical angle for glass is approximately:

(A) $20^\circ$

(B) $30^\circ$

(C) $42^\circ$

(D) $48^\circ$

88. Blue color of the sky is due to:

(A) Reflection

(B) Refraction

(C) Scattering

(D) Interference

89. The final image in an astronomical telescope is:

(A) Real and erect

(B) Real and inverted

(C) Virtual and inverted

(D) Virtual and erect

90. Least distance of distinct vision for a normal eye is:

(A) 100 cm

(B) 50 cm

(C) 25 cm

(D) Infinite

91. Rainbow formation is due to:

(A) Scattering

(B) Diffraction

(C) Dispersion

(D) None of these

92. Refractive index of diamond is about:

(A) 1

(B) 1.5

(C) 2.42

(D) 4.14

93. When a convex lens is immersed in water, its power:

(A) Increases

(B) Decreases

(C) Remains same

(D) Becomes zero

94. Combining two convex lenses (powers $P_1$ and $P_2$) gives total power:

(A) $P_1 + P_2$

(B) $P_1 \cdot P_2$

(C) $P_1/P_2$

(D) $P_1 – P_2$

95. Cylindrical lenses are used to correct:

(A) Myopia

(B) Hypermetropia

(C) Presbyopia

(D) Astigmatism

96. Who discovered the Diffraction of light?

(A) Fresnel

(B) Newton

(C) Grimaldi

(D) Young

97. In Interference, energy is:

(A) Destroyed

(B) Created

(C) Redistributed

(D) None of these

98. Brewster’s Law is:

(A) $\mu = \sin i_p$

(B) $\mu = \cos i_p$

(C) $\mu = \tan i_p$

(D) $\mu = \cot i_p$

99. Which of the following confirms the transverse nature of light?

(A) Interference

(B) Diffraction

(C) Polarization

(D) Refraction

100. Angle of deviation ($\delta$) for a thin prism is:

(A) $(\mu – 1)A$

(B) $(\mu + 1)A$

(C) $\mu A$

(D) $A/\mu$

101. Magnifying power of a simple microscope is:

(A) $1 + D/f$

(B) $D/f$

(C) $1 – D/f$

(D) $f/D$

102. For total internal reflection, angle of incidence must be:

(A) Equal to critical angle

(B) Smaller than critical angle

(C) Greater than critical angle

(D) Zero

103. In absence of atmosphere, the sky would appear from Earth:

(A) Blue

(B) Red

(C) White

(D) Black

104. As wavelength increases, the refractive index of a medium:

(A) Increases

(B) Decreases

(C) Remains constant

(D) Becomes zero

105. Soap bubble appears colored due to:

(A) Diffraction

(B) Interference

(C) Dispersion

(D) Reflection

Part F: Modern Physics

106. Energy of a photon ($E$) is:

(A) $h\nu$

(B) $h/\nu$

(C) $c\nu$

(D) $h\lambda$

107. Specific charge of an electron is:

(A) $1.76 \times 10^{11}\ C/kg$

(B) $1.8 \times 10^{-19}\ C/kg$

(C) $1.6 \times 10^{-19}\ C/kg$

(D) $9.1 \times 10^{-31}\ C/kg$

108. Dimension of Planck’s constant is:

(A) $[ML^2T^{-1}]$

(B) $[ML^2T^{-2}]$

(C) $[MLT^{-1}]$

(D) $[ML^2T^0]$

109. De-Broglie wavelength ($\lambda$) is:

(A) $h/mv$

(B) $mv/h$

(C) $h \cdot mv$

(D) $m/hv$

110. In photoelectric effect, the energy of emitted electrons depends on:

(A) Intensity of light

(B) Frequency of light

(C) Work function of metal

(D) Both (B) and (C)

111. Which series of hydrogen spectrum lies in visible region?

(A) Lyman series

(B) Balmer series

(C) Paschen series

(D) Pfund series

112. Atomic Nucleus consists of:

(A) Protons and Neutrons

(B) Protons and Electrons

(C) Neutrons and Electrons

(D) Neutrons only

113. 1 amu is equal to:

(A) $1.66 \times 10^{-27}\ kg$

(B) $1.6 \times 10^{-19}\ kg$

(C) $9.1 \times 10^{-31}\ kg$

(D) $10^{-20}\ kg$

114. The source of Sun’s energy is:

(A) Nuclear Fission

(B) Nuclear Fusion

(C) Chemical reaction

(D) None of these

115. Relation between Half-life ($T_{1/2}$) and decay constant ($\lambda$) is:

(A) $T_{1/2} = 0.693 / \lambda$

(B) $T_{1/2} = 0.693 \cdot \lambda$

(C) $T_{1/2} = \lambda / 0.693$

(D) $T_{1/2} = 1/\lambda$

116. Which particle is charge-less?

(A) $\alpha$-particle

(B) $\beta$-particle

(C) Proton

(D) Photon

117. According to Bohr’s 2nd postulate, angular momentum ($L$) is:

(A) $nh/2\pi$

(B) $h/2\pi$

(C) $n^2h/2\pi$

(D) $nh/\pi$

118. Decimal value of binary number $(1001)_2$ is:

(A) 9

(B) 12

(C) 15

(D) 10

119. Boolean expression for OR gate is:

(A) $A + B = Y$

(B) $A \cdot B = Y$

(C) $\bar{A} = Y$

(D) $A + B = 0$

120. Boolean expression for AND gate is:

(A) $A + B = Y$

(B) $A \cdot B = Y$

(C) $\bar{A} = Y$

(D) $\overline{A+B} = Y$

121. Boolean expression for NAND gate is:

(A) $\overline{A \cdot B} = Y$

(B) $A + B = Y$

(C) $\bar{A} = Y$

(D) $A \cdot B = Y$

122. Majority charge carriers in N-type semiconductor are:

(A) Protons

(B) Holes

(C) Electrons

(D) Neutrons

123. Majority charge carriers in P-type semiconductor are:

(A) Electrons

(B) Holes

(C) Neutrons

(D) Alpha particles

124. A Diode is used as a/an:

(A) Amplifier

(B) Oscillator

(C) Rectifier

(D) Modulator

125. How many types of Modulation are there?

(A) 2

(B) 3

(C) 5

(D) 10

126. Frequency range used for TV transmission is:

(A) 30 Hz – 300 Hz

(B) 30 kHz – 300 kHz

(C) 30 MHz – 300 MHz

(D) 30 GHz – 300 GHz

127. Cathode rays are:

(A) Stream of electrons

(B) Stream of protons

(C) Stream of neutrons

(D) Stream of photons

128. An $\alpha$-particle is a/an:

(A) Helium nucleus

(B) Hydrogen nucleus

(C) Electron

(D) Neutron

129. Moderator used in nuclear reactors is:

(A) Heavy water ($D_2O$)

(B) Ordinary water

(C) Cadmium

(D) Uranium

130. Solar cell is based on the principle of:

(A) Photoelectric effect

(B) Thermionic emission

(C) Nuclear fusion

(D) None of these

Part G: EM Waves & Communication

131. The nature of electromagnetic waves (EM Waves) is:

(A) Transverse

(B) Longitudinal

(C) Both

(D) None of these

132. Highest penetrating power is possessed by:

(A) $\alpha$-rays

(B) $\beta$-rays

(C) X-rays

(D) $\gamma$-rays (Gamma rays)

133. Order of wavelength of X-rays is:

(A) $10^{-10}\ m$ (1 Å)

(B) $10^{-7}\ m$

(C) $10^{-4}\ m$

(D) $10^{-2}\ m$

134. Relation between speed of light $c$ and $\mu_0, \epsilon_0$ in vacuum is:

(A) $c = 1/\sqrt{\mu_0 \epsilon_0}$

(B) $c = \sqrt{\mu_0 \epsilon_0}$

(C) $c = \mu_0 \epsilon_0$

(D) $c = \epsilon_0/\mu_0$

135. Waves used for Telecommunication are:

(A) Ultraviolet

(B) Infrared

(C) Microwaves

(D) Cosmic rays

136. Ozone layer absorbs:

(A) X-rays

(B) Ultraviolet (UV) radiation

(C) Infrared radiation

(D) Gamma rays

137. Color of visible light is determined by its:

(A) Wavelength (or frequency)

(B) Velocity

(C) Amplitude

(D) Intensity

138. Waves used in Radar are:

(A) Radio waves

(B) Microwaves

(C) X-rays

(D) Sound waves

139. Product of vacuum permeability ($\mu_0$) and permittivity ($\epsilon_0$) is:

(A) $1/c^2$

(B) $c^2$

(C) $1/c$

(D) $c$

140. Direction of propagation of EM waves is parallel to:

(A) $\vec{E}$

(B) $\vec{B}$

(C) $(\vec{E} \times \vec{B})$

(D) $(\vec{B} \times \vec{E})$

Part H: Mixed Important MCQs

141. A galvanometer of resistance $G$ requires a shunt to pass $1/n$ of the total current. Shunt value is:

(A) $G/n$

(B) $G/(n-1)$

(C) $G(n-1)$

(D) $G/n^2$

142. Faraday’s Law of induction is based on:

(A) Conservation of energy

(B) Conservation of charge

(C) Conservation of mass

(D) Conservation of momentum

143. Lenz’s Law is based on the conservation of:

(A) Charge

(B) Energy

(C) Momentum

(D) Mass

144. Capacitance of a spherical conductor in air is proportional to its:

(A) Mass

(B) Radius

(C) Area

(D) Volume

145. Unit of Self-inductance is:

(A) Weber

(B) Henry

(C) Ohm

(D) Gauss

146. 1 Tesla is equal to:

(A) $10^4$ Gauss

(B) $10^{-4}$ Gauss

(C) $10^2$ Gauss

(D) 1 Gauss

147. Light year is the unit of:

(A) Time

(B) Distance

(C) Energy

(D) Intensity of light

148. Film used for photography in fog is:

(A) Polaroid

(B) Infrared

(C) Ultraviolet

(D) Ordinary

149. LASER rays possess:

(A) Monochromaticity

(B) High coherence

(C) High intensity

(D) All of the above

150. When light travels from one medium to another, which property remains unchanged?

(A) Velocity

(B) Wavelength

(C) Frequency

(D) Refractive Index