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:

1.	0.1 V	2.	1.0 V
3.	0.2 V	4.	0.01 V

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:

A coil having an area $A_0$ is placed in a magnetic field which changes from $B_0$ $to$ $4B_0$ in time interval t. The average EMF induced in the coil will be:

1. $\frac{3A_0{B}_0}{t}$

2. $\frac{4A_0{B}_0}{t}$

3. $\frac{3B_0}{A_{0}t}$

4. $\frac{4B_0}{A_{0}t}$

A rod AB of length l is moving with constant speed v in a uniform magnetic field on a conducting U-shaped wire as shown. If the rate of loss of heat energy across resistance R is Q, then the force needed parallel to velocity to keep rod moving with constant speed v is:

1.  Qv

2.  $\frac{\mathrm{Q}}{\mathrm{v}}$

3.  $\frac{{\mathrm{Q}}^2}{\mathrm{v}}$

4.  ${\mathrm{Q}}^2\mathrm{v}$

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:

A rectangular loop of wire shown below is coplanar with a long wire carrying current \(I.\)
               
The loop is pulled to the right as indicated. What are the directions of the induced current in the loop and the magnetic forces on the left and right sides of the loop?

An electric potential difference will be induced between the ends of the conductor shown in the diagram when the conductor moves in the direction of:

1. P
2. Q
3. L
4. M