If a semicircular conducting loop \(ACB\) is rotating in the plane of paper with constant angular velocity \(\omega\) about \(O\), then which of the following graphs shows the variation of induced current \((I)\) with time \((t)\)? The magnetic field is perpendicular to the plane of the loop as shown in the figure.
               

1.		2.
3.		4.

A current-carrying cable is penetrating a loop as shown in the figure. If the magnitude of the current is decreasing with time, then the current induced in the loop is

1. Zero

2. Clockwise

3. Anticlockwise

4. Depends on the magnitude of the current

A solenoid has an inductance of 20 H and a resistance of 5 ohms. It is connected to a battery of 20 volts. The maximum magnetic energy stored in the magnetic field of the solenoid is

1. 40 J

2. 160 J

3. 320 J

4. 80 J

The slotting processes in a metallic sheet results in:

The square loop shown below is rotated about the axis PQ and magnetic field is perpendicular to the plane of the paper. The magnitude of induced emf in the loop is minimum when the plane of the loop:

1. is perpendicular to the plane of the paper.

2. is parallel to the plane of the paper.

3. makes 45$°$ angle with the plane of the paper.

4. makes 60$°$ angle with the plane of the paper.

A small square-shaped loop of edge length l is placed at the centre of a circular loop A of radius r with its plane perpendicular to the plane of the circular loop. The coefficient of mutual induction of this combination is 

1. Zero

2. $\frac{{\mu }_0\sqrt{2}l{r}^2}{3\pi }$

3. $\frac{{\mu }_0\sqrt{2}{l}^{2}r}{3}$

4. $\frac{{\mu }_0\sqrt{3}{l}^2}{2r}$

A horizontal ring of radius r spins about its vertical axis with an angular velocity $\omega$ in a uniform vertical magnetic field of magnitude B. The emf induced in the ring is

1. Zero

2. $\pi r^{2}B\omega$

3. $\frac{1}{2}B\omega r^2$

4. $B\omega r^2$

If N is the total number of turns in a coil, then the value of self-inductance varies as

1. N$°$

2. N

3. N²

4. $\sqrt{N}$

Eddy currents are produced in a material when it is:
 

Lenz's law associated with Faraday's laws of electromagnetic induction are consequence of the conservation of

1. Charge

2. Energy

3. Magnetic field

4. Mass