Explanation:
In a capacitor of capacitance C,
$\text{V}=\frac{\text{q}}{\text{C}}$
$\Rightarrow\frac{\text{dV}}{\text{dt}}=\frac{\text{i}}{\text{C}}=\frac{1\text{A}}{1\mu\text{F}}=\frac{10^6\text{V}}{\text{s}}$
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Assertion : A compass needle when placed on the magnetic north pole of the earth rotates in vertical direction.
Reason : The earth has only horizontal component of its magnetic field at the north poles.
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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. |
A very long straight wire carries a current I. At the instant when a charge +Q at point P has velocity 
, as shown, the force on the charge is
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(a) Opposite to OX |
(b) Along OX |
(c) Opposite to OY |
(d) Along OY |
The mass of the electron varies with
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(a) The size of the cathode ray tube |
(b) The variation of ‘g’ |
|
(c) Velocity |
(d) Size of the electron |
The correct graph between the maximum energy of a photoelectron and the inverse of wavelength of the incident radiation is given by the curve
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(a) A |
(b) B |
(c) C |
(d) None of the above |
Current provided by a battery is maximum when
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(a) Internal resistance equal to external resistance |
|
(b) Internal resistance is greater than external resistance |
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(c) Internal resistance is less than external resistance |
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(d) None of these |
$\text{Zero.}$
$\text{v}_0$
$\sqrt2\text{v}_0$
$2\text{v}_0$
A parallel beam of light is incident on a converging lens parallel to its principal axis. As one moves away from the lens on the other side on its principal axis, the intensity of light:
A 220 volt, 1000 W bulb is connected across a 110 volt mains supply. The power consumed will be
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(a) 1000 W |
(b) 750 W |
(c) 500 W |
(d) 250 W |