Question

The induction furnace is based on the heating effect of
A. Electric Field
B. Eddy Current
C. Magnetic Field
D. Gravitational Field

Answer 1

Hint: An induction furnace is an electric furnace which is used to melt metals like copper, aluminum, steel, ferrous and non ferrous metals by supplying heat using induction heating.

Complete step by step solution:
When a conductor is placed in a changing magnetic field, current is induced in the conductor. These induced currents are known as Eddy currents. In an induction furnace a very high frequency current is passed to produce heat. If the conductor has low resistance, then the magnitude of these currents will be very high due to which heat is produced in the conductor.

The heat energy is produced due to the loss of electric energy that is supplied to the conductor. Due to the change in magnetic field of the conductor, the free electrons will start moving in the form of whirlpools. The magnitude of these eddy currents can be calculated using Faraday’s second law of electromagnetic induction. The Eddy currents flow in the form of closed loops in a direction perpendicular to magnetic fields. Eddy currents are based on Faraday’s law of electromagnetic induction. Therefore, the heat gets generated in the induction furnace by Eddy currents.

Hence, option B is the correct answer.

Note: Apart from the induction furnace, Eddy currents have many more applications, which we see or use in our everyday life. They are used in energy meters, speedometers, galvanometers etc. But they also have some disadvantages. In a transformer or an electric motor, the coil that is used produces undesirable heat and dissipates electrical energy.