(A) A fuse in electric circuit is rated 4 A. Can it be used with an electric heater of rating 2 kW, 200 V? Explain your answer.

\(\displaystyle \mathrm{I}=\frac{\mathrm{P}}{\mathrm{V}}\) \[\mathrm{I}=\frac{2000}{200} \]

\(\displaystyle \mathrm{I}=10 \mathrm{~A}\)

Current passing through electric heater is 10A which is much more than rated value (4A) of fuse. Hence fuse will melt and break the circuit. So, it cannot be used.

An electromagnet is formed by wrapping a current carrying insulated copper wire in the form of coil around a magnetic material like soft iron core. / By placing a magnetic material like soft iron as a core material inside the current carrying solenoid.

Strength of electromagnet can be increased by increasing the (i) Number of turns of coil

(ii) Current flowing through the coil.