Question

Study the circuits shown in image carefully and answer the questions:

1) What happens to the iron pins when the circuit is switched 'ON' and when it is switched 'OFF'?
2) What conclusion do you draw from your observation?

Please answer both questions correctly​

Answer 1

Answer:

1) When the two ends of the coil are connected to a cell, a current passes through the coil and produces a magnetic effect. ... This is because when current is switched off in the coil of an electromagnet made of iron piece, then the iron piece loses all its magnetism.

2) Since the resistance is constant even when current and Voltage are very high, Ohms law is valid to a high accuracy. This shows that  resistivity of the alloy manganin is nearly independent of temperature.

Answer 2

Explanation:

1. The magnetism of an electromagnet remains as long as the current is flowing in its coil. ... Only iron is used for making electromagnets. This is because when current is switched off in the coil of an electromagnet made of iron piece, then the iron piece loses all its magnetism.