`AB` and `CD` are smooth, parallel rails, separated by a distance `L` and inclined to the horizontal at an angle `theta`. A uniform magnetic field of magnitude `B`, directed vertically upwards, exists in the region. `EF` is a conductor of mass `m`, carrying a current `i`. For `EF` to be in equilibrium

(i) `i` must flow from `E` to `F`
(ii) `B i L = m g tan theta`
(iii) `B i L = m g sin theta`
(iv) `B i L = m g`

Options

A. (i), (ii)
B. (ii), (iv)
C. (ii), (iii)
D. (i), (iv)

Answer

A

Explanation

`mg = sin theta = B cos theta iL`
`BiL = mg tan theta`