Figure shows a conducting rod of negligible resistance that can slide on smooth U-shaped rail made of wire of resistance `1Omega//m`. Position of the conducting rod at `t=0` is shown. A time dependent magnetic field `B=2t` tesla is switched on at `t=0`

The current in the loop at `t=0` due to induced emf is

Options

A. `0.16A`, clockwise
B. `0.08A,` clockwise
C. `0.16A`, anti clockwise
D. zero

Answer

A

Explanation

`|e|=(dphi)/(dt)=S(dB)/(dt)`
`=(0.2xx0.4)(2)=0.16V`
`i=(|e|)/R=0.16/((1)(40+40+20)xx10^2)`
`=0.16A`
`o.` Magnetic field passing through the loop is increasing. So, induced curret should produce `ox` magnetic field. Hence induced current is clockwise.