Two coils A and B are separated by a certain distance. If a current of 4 A flows through A, a magnetic flux of `10^(-3)Wb` passes through B (no current through B). If no current passes through A and a current of 2 A passes through B, then the flux through A is.

Options

A. `5xx10^(-3)Wb`
B. `4xx10^(-4)Wb`
C. `5xx10^(-4)Wb`
D. `2xx10^(-3)Wb`

Answer

C

Explanation

Magnetic flux linked with coil
`phi_(B)=MI_(A)`
`:. M=(phi_(B))/(I_(A))=(10^(-3))/(4)` henary
Magenetic flux linked with coul A
`phi_(A)=MI_(B)=(10^(-3))/(4)xx2=5xx10^(-4)Wb`