In a magnetic field of `0.05T`, area of a coil changes from `101 cm^(2)` to `100 cm^(2)` without changing the resistance which is `2Omega`. The amount of charge that flow during this period is

Options

A. `2.5xx10^(-6)C`
B. `2xx10^(-6)C`
C. `10^(-6)C`
D. `8xx10^(-6)C`

Answer

A

Explanation

`therefore` Magnetic flux, `phi=B.A`
`therefore` Change in flux, `dphi=B.dA`
`=0.05(101-100)xx10^(-4)=5xx10^(-6)Wb`
`therefore" Change, dq"=(dphi)/(R)=(5xx10^(-6))/(2)=2.5xx10^(-6)C`