Question

A generator or dynamo works on the principle:

• A. Heating effect of electric current
• B. Electromagnetic induction
• C. Chemical effect of electric current
• D. All of the above

Answer 1

Answer: (B)

Electromagnetic induction

Magnetic effect of electric current:

Due to this effect, magnetic field is induced near a current carrying wire. Electromagnets are designed on this principle.

Electromagnetic Induction:

Due to this effect, an emf is induced in a coil when magnetic field lines passing through the coil changes. This is the principle used in a generator or a dynamo.

Chemical effects of electric current:

Due to this effect, chemical composition of compounds through which the electric current passes changes. Electrolysis is based on this phenomenon.

Heating effect of electric current:

Due to this effect, resistor heats up when electric current passes through it. This phenomenon is used in electrical fuses.