Question

describe an experiment to show that the current is set up in a closed loop when an external magnetic field passing through the loop increases or decreases​

Answer 1

Yes

This is very hard

I don't think anyone will answer

Answer 2

Answer:

In the absence of external magnetic field only Earth’s magnetic field act due to which magnetic compass needle pointing north and south direction.

When a bar magnet or a current carrying loop is brought near it, then it produces magnetic field, due to which magnetic fields of the compass needle and the bar magnet (or current carrying loop) interact with each other causing a deflection in the needle.

In the absence of external magnetic field only Earth’s magnetic field act due to which magnetic compass needle pointing north and south direction.

The salient features of magnetic field lines are

Magnetic lines form closed and continuous curve

Magnetic lines is emerges from north-pole to south-pole outside the magnet

Magnetic field lines never intersect each other

Closer the magnetic lines represent stronger magnetic field and vice-versa.