Real-World Applications of Electromagnetic Devices

This video tutorial explores the real-world applications of electromagnets, starting with a basic understanding of what an electromagnet is and how it functions. It then delves into specific applications such as circuit breakers, electric bells, relays, and scrapyard cranes, explaining how electromagnets are integral to their operation. Each section provides a detailed explanation of the mechanisms involved, highlighting the role of electromagnets in generating magnetic fields and controlling electrical circuits.

What happens to the iron core of an electromagnet when the current is turned off?

• It loses its magnetism.

• It generates a stronger magnetic field.

• It starts to heat up.

• It becomes permanently magnetized.

In a circuit breaker, what role does the spring play?

• It generates the magnetic field.

• It keeps the arm in the pivoted position after the current stops.

• It increases the current flow.

• It acts as a conductor.

How does a circuit breaker prevent current from flowing?

• By reducing the resistance.

• By breaking the contact between two arms.

• By cooling the circuit.

• By increasing the voltage.

What causes the bell to ring in an electric bell system?

• The continuous flow of current.

• The iron armature striking the bell.

• The decrease in resistance.

• The increase in voltage.

In an electric bell, what happens when the circuit is broken?

• The iron armature becomes magnetized.

• The electromagnet turns off.

• The bell rings continuously.

• The current increases.

What is the primary function of a relay in an electrical circuit?

• To generate electricity.

• To increase the voltage.

• To control a larger current with a smaller current.

• To decrease the resistance.

How does a scrapyard crane use an electromagnet?

• To measure weight.

• To lift and move vehicles.

• To generate electricity.

• To melt metal objects.