A coil is wound as a transformer of rectangular cross-section. If all the linear dimensions of the transformer are increased by a factor 2 and the number of turns per unit length of the coil remain the same, the self inductance increased by a factor of
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(a) 16 |
(b) 12 |
(c) 8 |
(d) 4 |
(c) 8
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Assertion : The permeability of a ferromagnetic material is independent of the magnetic field.
Reason : Permeability of a material is a constant quantity.
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(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
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(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
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(c) If assertion is true but reason is false. |
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(d) If the assertion and reason both are false. |
If luminous efficiency of a lamp is 2 lumen/watt and its luminous intensity is 42 candela, then power of the lamp is
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(a) 62 W |
(b) 76 W |
(c) 138 W |
(d) 264 W |
The maximum velocity of an electron emitted by light of wavelength λ incident on the surface of a metal of work function ∅, is (Where h = Planck's constant, m = mass of electron and c = speed of light.)
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(a) |
(b) |
(c) |
(d) |
The angle of dip at a place on the earth gives
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(a) The horizontal component of the earth's magnetic field |
| (b) The location of the geographic meridian |
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(c) The vertical component of the earth's field |
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(d) The direction of the earth's magnetic field |
In a Young's double slit experiment the source S and the two slits A and B are vertical with slit A above slit B. The fringes are observed on a vertical screen K. The optical path length from S to B is increased very slightly (by introducing a transparent material of higher refractive index) and the optical path length from S to A is not changed, as a result the fringe system on K moves
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(a) Vertically downwards slightly |
(b) Vertically upwards slightly |
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(c) Horizontally, slightly to the left |
(d) Horizontally, slightly to the right |
A source voltage of 8V drives the diode in fig. through a current-limiting resistor of 100 ohm. Then the magnitude of the slope load line on the V-I characteristics of the diode is
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(a) 0.01 |
(b) 100 |
(c) 0.08 |
(d) 12.5 |
