A train of mass 100 tons `(1` tons `=1000kg)` runs on a meter gauge track ( distance between the two rails is `1m)`. The coefficient of friction between the rails and the train is `0045`. The train is powered by an electric engine of `90%` efficiency. The train is moving with uniform speed of `72 kmph` at its highest speed limilt . Horizontal and vertical component of earth's magnetic field and `B_(H)=10^(-5)T` and `B_(V)=2xx10^(-5)T`. Assume the body of the train and rails to be perfectly conducting.
The potential difference between the two rails is

Options

A. `100 mu V`
B. `200 mu V`
C. `400 mu V`
D. `800 mu V`

Answer

C

Explanation

`(C ) epsilon=B_(_|_)Vl=B_(V).Vl`
`=2xx10^(-5)xx20xx1=40xx10^(-5)`Volts