Understanding Electromagnetic Relays and Telephone Earpieces

What is the primary function of an electromagnetic relay?

• To act as an automatic switch

• To store electrical energy

• To generate electricity

• To open and close circuits under control

What component is essential for the operation of an electromagnetic relay?

• A capacitor

• A resistor

• An electromagnet

• A battery

What is the purpose of the second circuit in an electromagnetic relay?

• To provide backup power

• To connect to electrical appliances

• To control the electromagnet

• To reduce voltage

Why is it dangerous to switch high voltage currents directly?

• It can cause a short circuit

• It can overheat the circuit

• It may lead to electric shock

• It will drain the battery quickly

How does the relay ensure safety when dealing with high voltage?

• By using a thicker wire

• By using a fuse

• By using a second circuit to control the switch

• By grounding the circuit

What happens when the current in the electromagnet of a relay is switched off?

• The switch remains closed

• The machine stops operating

• The machine continues to operate

• The electromagnet becomes stronger

How does a telephone earpiece convert sound energy?

• By amplifying the sound

• By converting sound to electric current

• By using a speaker

• By using a microphone

What happens to the diaphragm in a telephone earpiece when the current increases?

• It breaks

• It vibrates

• It changes color

• It remains static

What is the role of the electromagnet in a telephone earpiece?

• To store sound energy

• To convert sound to light

• To create a magnetic field that moves the diaphragm

• To amplify sound

What is the relationship between the frequency of the current and the sound in a telephone?

• The sound frequency is double the current frequency

• The current frequency is higher

• They are unrelated

• The current frequency matches the sound frequency