Physics Chapter 20 Important Short Questions with Answers

 ❓ Q1: What is magnetic flux?

Ans: Magnetic field lines passing through a surface is called magnetic flux.

❓ Q2: What is unit of magnetic flux?

Ans: Weber (Wb).

❓ Q3: What is electromagnetic induction?

Ans: Production of current in a conductor due to changing magnetic field.

❓ Q4: State Faraday’s law.

Ans: Induced EMF is proportional to rate of change of magnetic flux.

❓ Q5: What is Lenz’s law?

Ans: Direction of induced current opposes the change causing it.

❓ Q6: What is transformer?

Ans: Device used to increase or decrease voltage.

❓ Q7: What are types of transformer?

Ans: Step-up and Step-down transformer.

❓ Q8: What is AC current?

Ans: Current that changes direction continuously.

❓ Q9: What is DC current?

Ans: Current that flows in one direction.

❓ Q10: What is generator?

Ans: Device that converts mechanical energy into electrical energy.

❓ Q11: What is mutual induction?

Ans: Induction of current in one coil due to change in current in another coil.

❓ Q12: What is self induction?

Ans: Induction of current in same coil due to change in its own current.