A rod of 5m length is moving perpendicular to uniform magnetic field of intensity `2 xx 10^(-4) "Wb/m"^2`. If the acceleration of rod is `2ms^(-2)`, th rate of increase of the induced emf is____

Options

A. `20xx10^(-4) "V/sec"^2`
B. `20xx10^(-4)V`
C. `20xx10^(-4)` Vs
D. `20xx10^(-4)` V/s

Answer

D

Explanation

Magnitude of induced emf E=Bvl
Taking derivation w.r.t. t,`"dE"/"dt"=d/"dt"` (Bvl)
B and l are constant `therefore (dE)/(dt)=B(dv)/(dt)l`
`therefore (dE)/(dt)=Bal " " [because (dv)/(dt)=a]`
`=2xx10^(-4)xx2xx5`
`therefore (dE)/(dt)=20xx10^(-4)` V/s