2 A current is passed through a solenoid which has 5 cm diameter, 10 turns and 10 cm length. Now, near to one of its two ends, a circular loop of radius 2 cm is kept perpendicular to axis of solenoid. Then magnetic flux passing through this loop is ...... Wb. (`mu_0=4pixx10^(-7)TmA^(-1)` and take `pi^@`=10)

Options

A. `3.2xx10^(-8)`
B. `3.2xx10^(-7)`
C. `3.2xx10^(-9)`
D. `3.2xx10^(-6)`

Answer

B

Explanation

Magnetic field inside the solenoid is :
`B=mu_0nI`
`B=mu_0 (N/l)I`
Now, magnetic flux linked with the loop , mentioned in the statement is :
`phi=BA cos theta`
`=(mu_0NI)/l xx pir^2xxcos0^@`
`=(4pixx10^(-7)xx10xx2xxpixx4xx10^(-4))/0.1`
`=32pi^2xx10^(-9)`
`=3.20xx10^(-7)`
`=3.2xx10^(-7)` Wb