A \(1~\text{m}\) long metallic rod is rotating with an angular frequency of \(400~\text{rad/s}\)$$ about an axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring. A constant and uniform magnetic field of \(0.5~\text{T}\) parallel to the axis exists everywhere. The emf induced between the centre and the ring is:
1. \(200~\text{V}\)
2. \(100~\text{V}\)
3. \(50~\text{V}\)
4. \(150~\text{V}\)

Current in a circuit falls from \(5.0~\text A\) to \(0~\text A\) in \(0.1~\text{s}\). If an average emf of \(200~\text V\) is induced, the self-inductance of the circuit is:
1. \(4~\text H\) 
2. \(2~\text H\) 
3. \(1~\text H\) 
4. \(3~\text H\) 

A pair of adjacent coils has a mutual inductance of \(1.5~\text H.\) If the current in one coil changes from \(0\) to \(20~\text A\) in \(0.5~\text s,\) what is the change of flux linkage with the other coil?

In which of the following devices, the eddy current effect is not used?

1. Electric heater

2. Induction furnace

3. Magnetic braking in train

4. Electromagnet

A cylindrical magnet is kept along the axis of a circular coil. On rotating the magnet about its axis, the coil will have induced in it:

The magnetic flux through a coil varies with time \(t\) as shown in the diagram. Which graph best represents the variation of the emf \(E\) induced in the coil with time \(t\)?

1.		2.
3.		4.

A bar magnet is made to fall through a long surface copper tube. The speed \((v)\) of the magnet as a function of time \((t)\) is best represented by:

       
1. \(a\)
2. \(b\)
3. \(c\)
4. \(d\)

When a conducting wire \(XY\) is moved towards the right, a current flows in the anti-clockwise direction. Direction of magnetic field at point \(O\) is: