Whenever the magnetic field through a coil is changed,a potential difference is produced in the coil.

$(a)$ An electric current is passed in a horizontal copper wire from east to west. Explain your observations when a compass needle is placed $(i)$ below this wire,$(ii)$ above the wire. Draw inference from your observations.
$(b)$ List the factors on which the strength of the magnetic field due to a straight conductor carrying current depend. How should these be changed to decrease magnetic field at a point?

$A$ fuse is a $.......$ wire.

What type of core is used to make an electromagnet?

The induced potential difference produced in a coil when a magnet is inserted into it does not depend upon:

Describe an experiment to demonstrate the force acting on a current-carrying conductor placed in a magnetic field.