I:	A small magnet takes a longer time in falling into a hollow metallic tube without touching the wall.
II:	There is an opposition to motion due to the production of eddy currents in a metallic tube.

Choose the correct option for the above statements:

1.	Both I and II are true and II is the correct explanation for I.
2.	Both I and II are true and II is not the correct explanation for I.
3.	I is true but II is false.
4.	I is false but II is true.

A coil is wound of a frame of rectangular cross-section. If the linear dimensions of the frame are doubled and the number of turns per unit length of the coil remains the same, then the self inductance increases by a factor of:

An aeroplane in which the distance between the tips of wings is 50 m is flying horizontally with a speed of 360 km/hr over a place where the vertical component of earth magnetic field is $2.0\times {10}^{-4}$ $\mathrm{weber}/{\mathrm{m}}^2$. The potential difference between the tips of wings would be:

A rectangular, a square, a circular, and an elliptical loop, all in the (x-y) plane, are moving out of a uniform magnetic field with a constant velocity, $\overrightarrow{\mathrm{v}}=\mathrm{v}\hat{\mathrm{i}}$. The magnetic field is directed along the negative z-axis direction. The induced emf, during the passage of these loops out of the field region, will not remain constant for:

A conducting circular loop is placed in a uniform magnetic field of 0.04 T with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at a rate of 2 mm/s. The induced e.m.f. in the loop when the radius is 2 cm is:

1. \(3.2\pi ~\mu V\)

2. \(4.8\pi ~\mu V\)

3. \(0.8\pi ~\mu V\)

4. \(1.6\pi ~\mu V\)

A coil of self-inductance \(L\) is connected in series with a bulb \(\mathrm{B}\) and an AC source. The brightness of the bulb decreases when:

A coil has 1,000 turns and 500 ${\mathrm{cm}}^2$ as its area. The plane of the coil is placed at right angles to a magnetic field of $2\times {10}^{-5}$ $Wb/m^2$. The coil is rotated through  \(180^{0}\)$$  in 0.2 seconds. The average e.m.f. induced in the coil, in milli-volts, is:

The current in a coil varies with time t as $\mathrm{I}$ $=$ $3{\mathrm{t}}^2+$ $2\mathrm{t}$. If the inductance of coil be 10 mH, the value of induced e.m.f. at \(t=2~\mathrm{s}\) will be:
1. \(0.14~\mathrm{V}\)
2. \(0.12~\mathrm{V}\)
3. \(0.11~\mathrm{V}\)
4. \(0.13~\mathrm{V}\)

A coil of a mean area of 500 $c{m}^2$ and 1000 turns is held perpendicular to a uniform field of 0.4 Gauss. The coil is turned through $180°$ in $\frac{1}{10}$ seconds. The average induced e.m.f. is:

The network shown in figure is a part of a complete circuit. If at a certain instant, the current 'i' is 10 A and is increasing at the rate of $4\times {10}^3$ A/sec, then $V_A-V_B$ is: