Question

magnetic
10. If you have a coil of 10 number of turns in which their radii are in A.P .A bar magnet of 0.25 T magnetic field is inserted into the coil quickly through the biggest turn .If the time taken for the magnet to move from the first turn to the last turn is 10 seconds.Is there any induced current generated?. What is the magnetic flux linked with the fifth turn?​

Answer 1

Given that,

Number of turns in the coil is 10

Magnetic field of magnet is 0.25 T

The time taken for the magnet to move from the first turn to the last turn is 10 seconds.

To find,

The magnetic flux linked with the fifth turn.

Solution,

In this case, a bar magnet is inserted into the coil quickly through the biggest turn. Due to this, the magnetic flux linked with the coil changes. So, an emf will be induced in it. As a result, the induced current is generated.

Magnetic flux is given by :

$\phi=BA$

A is area, $A=\pi r^2$, r is radius

For the fifth turn,

$\phi=5NBA$

So,

$\phi=5\times 10\times 0.25\times \pi \times r^2\\\\\phi=39.26r^2\ Wb$

So, the magnetic flux linked with the fifth turn is $39.26r^2\ Wb$.