A bar magnet of length 10 cm and having the pole strength equal to 10-3 Wb is kept in a magnetic field having magnetic induction (B) equal to 4 π × 10-3 T. It makes an angle of 30° with the direction of magnetic induction. The value of the torque acting on the magnet is

Question

A bar magnet of length 10 cm and having the pole strength equal to 10-3 Wb is kept in a magnetic field having magnetic induction (B) equal to 4 π × 10-3 T. It makes an angle of 30° with the direction of magnetic induction. The value of the torque acting on the magnet is (A) 2 π × 10-7 Nm (B) 2 π × 10-5 Nm (C) 0.5 Nm (D) 0.5 × 102 Nm

Tardigrade Admin · Accepted Answer

Torque, τ=M B sin θ =0.1 × 10-3 × 4 π × 10-3 × sin 30° =10-7 × 4 π × (1/2) =2 π × 10-7 N m

$2 π \times 1 0^{- 7} N m$

$2 π \times 1 0^{- 5} N m$

$0.5 N m$

$0.5 \times 1 0^{2} N m$

Torque, $τ = MB sin θ$
$= 0.1 \times 1 0^{- 3} \times 4 π \times 1 0^{- 3} \times sin 3 0^{\circ}$
$= 1 0^{- 7} \times 4 π \times \frac{1}{2}$
$= 2 π \times 1 0^{- 7} N m$

Q. A bar magnet of length 10cm and having the pole strength equal to 10−3Wb is kept in a magnetic field having magnetic induction (B) equal to 4π×10−3T. It makes an angle of 30∘ with the direction of magnetic induction. The value of the torque acting on the magnet is

2π×10−7Nm

2π×10−5Nm

0.5Nm

0.5×102Nm

Torque, τ=MBsinθ =0.1×10−3×4π×10−3×sin30∘ =10−7×4π×21​ =2π×10−7Nm

$2 π \times 1 0^{- 7} N m$

$2 π \times 1 0^{- 5} N m$

$0.5 N m$

$0.5 \times 1 0^{2} N m$

Torque, $τ = MB sin θ$
$= 0.1 \times 1 0^{- 3} \times 4 π \times 1 0^{- 3} \times sin 3 0^{\circ}$
$= 1 0^{- 7} \times 4 π \times \frac{1}{2}$
$= 2 π \times 1 0^{- 7} N m$