Question

in which devices the Eddy current effect is not used​

Answer 1

Answer:

The Eddy current effect is not used in the devices called electric heaters.

Explanation:

Eddy current techniques are commonly used for  nondestructive examination and there are many devices which indeed use this Eddy Current Effect.

For example,

(1) Induction furnace

(2) Magnetic braking in train;

and the (3) Electromagnet

However, the electric heaters do not use this effect in their nondestructive examination.

Answer 2

Eddy currents effect is not used in hair dryer and electric heaters because their efficiency is 100%. 100% efficiency means all the energy is used to do useful work. The function of electric heater and hair dryer is to produce heat, and all the energy supplied to them is finally converted into heat. that's why they are 100% efficient.