A solenoid is 1.5 m long and its inner diameter is 4.0 cm . It has three layers of windings of 1000 turns each and carries a current of 2.0 amperes. The magnetic flux for a cross-section of the solenoid is nearly

Options

A. `4.1 xx 10^(-5)`weber
B. `5.2 xx 10^(-5)` weber
C. `6.31 xx10^(-3)` weber
D. `2.5 xx 10^(-7)` weber

Answer

C

Explanation

`B=mu_0nI=mu_0N/lI`
`rarrB=4pixx10^-7xx3000/1.5xx2`
`=16pixx10^-4T`
f = BS = `16pxx10^-4xxpxx4xx10^-4`
`=6.31xx10^-3Wb`