A coil having n turns and resistance `R Omega` is connected with a galvanometer of resistance `4R Omega`. This combination is moved in time t seconds from a magnetic field `W_(1)` weber to `W_(2)` weber. The induced current in the circuit is

Options

A. `-(W_(2)W_(1))/(5Rnt)`
B. `-(n(W_(2)W_(1)))/(5Rt)`
C. `-(W_(2)W_(1))/(Rnt)`
D. `-(n(W_(2)W_(1)))/(Rt)`

Answer

B

Explanation

`i=(e)/(R')=(-dphi//dt)/(R')=(-(W_(2)-W_(1))n)/(5Rt)`