Eddy currents are used in:

1. Induction furnace

2. Electromagnetic brakes

3. Speedometers

4. All of these

The slotting processes in a metallic sheet results in:

Eddy currents are induced when:

1. A metal block is kept in a changing magnetic field.

2. A metal block is kept in a uniform magnetic field.

3. A coil is kept in a uniform magnetic field.

4. Current is passed in a coil.

Choose the correct option for the above statements:

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