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

`B=0.5T , A_(1)=101 cm^(2) =101xx10^(-4) m^(2)`
`A_(2)=100 cm^(2)=100xx10^(-4) m^(2)`
`R=2 Omega`
Amount of charge flowing is
`q=(BDeltaA)/R=(0.50xx(101xx10^(-4)-100xx10^(-4)))/2`
`=(0.05xx1xx10^(-4))/2=2.5xx10^(-6) C`