Question

For the coil shown in the figure what must be done to induce a clockwise current ?

• A. Either move the north pole of a magnet down into the coil, or move the south pole of the magnet up out of the coil
• B. Either move the south pole of a magnet down into the coil, or move the north pole of the magnet up out of the coil
• C. Move either pole of the magnet down into the coil.
• D. Move either pole of the magnet up into the coil.

Answer 1

Answer: (B)

Let us, make a random pole North and South in magnet and taking two situations. In fig (1) $\overrightarrow{B}$. shows magnetic field lines in the magnet.

In fig (2) the magnet field in the coil decreases as magnet move up current induced clockwise. So that to maintain constant flux. It means North pole move out or south pole move into the coil current will be clockwise.

In fig (3) magnetic flux decreases as south pole down into the coil current induced clockwise to maintain constant magnetic flux.