In Young’s experiment, the third bright band for light of wavelength 6000Å coincides with the fourth bright band for another source of light in the same arrangement. Then the wavelength of second source is
An electric dipole of length 1 cm is placed with the axis making an angle of 30⁰ to an electric field of strength 10⁴ NC⁻¹. If it experiences a torque of Nm, the potential energy […]
Small drops of the same size are charges to V volt each. If n such drops coalesce to form a single large drop, its potential will be
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(a) Vn (b) V/n (c) Vn¹/³ […]
If the self inductance of 500 turn coil is 125 mH, then the self inductance of similar coil of 800 turns is
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(a) 48.4 mH (b) 200 mH (c) 187.5 mH (d) 320 […]
The flux linked with a circuit is given by φ=t³+3t-7. The graph between time (x-axis) and induced emf (y-axis) will be a
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(a) straight line with negative intercept (b) straight line with […]
When a Daniel cell is connected in the secondary circuit of a potentiometer, the balancing length is found to be 540 cm. If the balancing length becomes 500 cm when the cell is short circuited […]
The drift velocity of the electrons in a copper wire of length 2 m under the application of a potential difference of 200 V is 0.5 ms⁻¹. Their mobility is (in m² V⁻¹ s⁻¹)
The nuclear radius of a certain nucleus is 7.2 fm and it has a charge of 1.28×10⁻¹⁷ C. The number of neutrons inside the nucleus is
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(a) 136 (b) 142 (c) 140 […]
An alternating voltage e=200s in100t is applied to a series combination of R= 30Ω and an inductor of 400 mH. The power factor of the circuit is
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(a) 0.01 (b) 0.05 (c) […]
The height of the dam, in an hydroelectric power station is 10 m. In order to generate 1 MW of electric power, the mass of water (in Kg) that must fall per second on the […]
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