Question

Torque acting on a rectangular coil carrying current 'l' situated parallel to magnetic field of induction 'B', having number of turns 'n' and area 'A' is ______.

Options

• `"ni"(hat"A"*hat"B")`

• `"nBA"/"i"`

• `"ni"("A" xx "B")`

• `"iBA"/"n"`

Answer 1

Torque acting on a rectangular coil carrying current 'l' situated parallel to magnetic field of induction 'B', having number of turns 'n' and area 'A' is `underline("ni"("A" xx "B"))`.

Explanation:

When a current-carrying coil Is placed in a magnetic field, the coil experienced a torque given by

τ = M × B

where, M =magnetic moment= niA

∴ τ = ni(A × B)

where, n = number of turns,
i = current flowing in coil
and A = area of coil