An inductor (L = 20 H), a resistor (R = 100 \(\Omega\)) and a battery (E = 10 V) are connected in series. After a long time, the circuit is short-circuited and then the battery is disconnected. Find the current in the circuit at 1 ms after short-circuiting.

1.  4.5 x 106 A
2.  3.2 x 10-5 A
3.  9.8 x 10-6 A
4.  6.7 x 10-4 A

Subtopic:  Different Types of AC Circuits |
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Two charges of + 10 \(\mu\text C\) and +20 \(\mu\text C\) are separated by a distance of 2 cm. The net potential (electric) due to the pair at the middle point of the line joining the two changes, is:

1.  27 MV
2.  18 MV
3.  20 MV
4.  23 MV

Subtopic:  Electric Potential |
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A copper rod of length 20 cm and cross-sectional area 2 mm2 is joined with a similar aluminium rod as shown below,

The resistance of a pair of rods is:
( and  \((\rho_{_{al}}=2.6\times10^{-6})~\Omega-m\) and \((\rho_{_{Cu}}=1.7\times10^{-8})~\Omega-m\)

1.  1.0 m\(\Omega\)
2.  2.0 m\(\Omega\)
3.  3.0 m\(\Omega\)
4.  None of these

Subtopic:  Combination of Resistors |
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A particle is subjected to two simple harmonic motions along the X-axis while the other is along a line making an angle of 45° with the X-axis. The two motions are given by \(x = x_0\) sin \(\omega t\) and \(s = s_0\) sin \(\omega t\). The amplitude of the resultant motion is:
1. \(x_0+s_0+2x_0s_0\)
2. \(\sqrt{x^2_0+s^2_0}\)
3. \(\sqrt{x^2_0+s^2_0+2x_0s_0}\)
4. \(x^2_0=s^2_0+\sqrt2x_0s_0~^{1/2}\)

Subtopic:  Simple Harmonic Motion |
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What is the change in the volume of \(1.0~\mathrm{L}\) kerosene when it is subjected to an extra pressure of \(2.0 \times 10^5 \mathrm{~Nm}^{-2}\) from the following data?
(The density of kerosene \(=800~\mathrm{kgm^3}\) and the speed of sound in kerosene \(=1330~\mathrm{ms^{-1}}\))
1. \( 0.97 \mathrm{~cm}^{-3} \)
2. \( 0.66 \mathrm{~cm}^{-3} \)
3. \( 0.15 \mathrm{~cm}^{-3} \)
4. \(0.59 \mathrm{~cm}^{-3}\)

Subtopic:  Elasticity |
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A \(4\) kg block is suspended from the ceiling of an elevator through a spring having a linear mass density of \(19.2 \times 10^{-3} \mathrm{~kg} \mathrm{~m}^{-3} \). Find the speed with respect to the spring with which a wave pulse can proceed on the spring if the elevator accelerates up at the rate of \(2.0\) ms-2.
(Take \(g=10\) ms-2.)
1. \( 30 \mathrm{~m} / \mathrm{s} \)
2. \(42 \mathrm{~m} / \mathrm{s} \)
3. \( 46 \mathrm{~m} / \mathrm{s} \)
4. \( 50 \mathrm{~m} / \mathrm{s} \)

Subtopic:  Wave Motion |
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The lower end of the capillary tube is immersed in mercury. The level of mercury in the tube is found to be 2 cm below the Outer level. If the same tube is immersed in water, up to what height will the water rise in the capillary?

1.  5.9
2.  4.9
3.  2.9
4.  1 .9
Subtopic:  Capillary Rise |
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What is the increase in pressure required to decrease the volume of water sample by \(0.01\%\)?. (Bulk modulus of water \(=2.1 \times 10^9 \mathrm{~Nm}^{-2}\))
1. \(4.3 \times 10^4 \mathrm{~N} / \mathrm{m}^2 \)
2. \( 1.8 \times 10^7 \mathrm{~N} / \mathrm{m}^2 \)
3. \( 2.1 \times 10^5 \mathrm{~N} / \mathrm{m}^2 \)
4. \(3.7 \times 10^4 \mathrm{~N} / \mathrm{m}^2\)

Subtopic:  Elasticity |
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Water level is maintained in a cylindrical vessel up to a fixed height \(H.\) The vessel is kept on a horizontal plane. At what height above the bottom should a hole be made in the vessel, so that the water stream coming out of the hole strikes the horizontal plane of the greatest distance from the vessel? 

1. \(h=\frac{H}{2}\)
2. \(h=\frac{3H}{2}\)
3. \(h=\frac{2H}{3}\)
4. \(h=\frac{3}{4}H\)

Subtopic:  Bernoulli's Theorem |
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The figure shows a spring + block + pulley system which is light. The time period of mass would be:

1. \(2\pi\sqrt{\frac{k}{m}}\)
2. \(\frac{1}{2\pi}\sqrt{\frac{k}{m}}\)
3. \(2\pi\sqrt{\frac{m}{k}}\)
4. None of these

Subtopic:  Simple Harmonic Motion |
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