Question

In which of the following devices, the eddy current effect is not used?
A. Induction furnace
B. Magnetic braking in train
C. Electromagnet
D. Electric heater

Answer 1

Hint: Before we proceed with the question, we need to know about the eddy currents. An emf is induced in a conductor Whenever the magnetic flux is linked with a sheet of conducting material or a block of metal, changes. These induced currents flow in closed paths in planes perpendicular to the lines of induction in the conductor. Such currents are called eddy currents. Now let’s discuss this question.

Complete step by step solution:
An induction furnace is defined as an electrical furnace in which the heat is applied by induction heating of metal. Here, a coil carrying alternating current surrounds the container of a conductor or metal. Since a coil carrying current produces a magnetic field, the eddy currents are induced in the metal and the circulation of these currents produces extremely high temperatures.

A magnetic train generates eddy currents using two sets of magnets, one to repel and push the train up off the track, and another to move the elevated train ahead, using lack of friction. When electricity is passed through the electromagnet, the magnetic field lines are generated in turn eddy currents are induced.

Electric heaters contain nichrome wires. When electricity is made to pass through this, then heat will be generated and it is released. Here the eddy currents are not produced, it is just a property of a conductor.

Hence, Option D is the correct answer

Note: A lot of energy will be lost in the form of heat and due to this heat loss, the life of the appliances gets reduced.