The magnetic field produced in a straight conducting wire on passing the current through it is ............ .

Four circular loops of radii $1 \; CM$,$2 \; CM$,$3 \; CM$,and $4 \; CM$ carry the same electric current. At the center of which loop will the magnetic field be the strongest?

$(a)$ What is an electromagnet? What does it consist of?
$(b)$ Name one material in each case which is used to make a: $(i)$ permanent magnet $(ii)$ temporary magnet.
$(c)$ Describe an activity to show how you can make an electromagnet in your school laboratory.

$(a)$ Electric fuse is an important component of all domestic circuits. Why?
$(b)$ An electric oven of rating $2 \, kW, 220 \, V$ is operated in a domestic circuit with a current rating of $5 \, A$. What result would you expect? Explain.

Explain what is short circuiting and overloading in an electric supply.

Name four appliances wherein an electric motor,a rotating device that converts electrical energy to mechanical energy,is used as an important component. In what respect are motors different from generators?