Torques τ1 and τ2 are required for magnetic needle to remain perpendicular to the magnetic fields B1 and B2 at two different places. The ratio B1 / B2 is

Question

Torques τ1 and τ2 are required for magnetic needle to remain perpendicular to the magnetic fields B1 and B2 at two different places. The ratio B1 / B2 is (A) (τ2/τ1) (B) (τ1/τ2) (C) (τ1+ τ2/τ1-τ2) (D) (τ1-τ2/τ1+τ2)

Tardigrade Admin · Accepted Answer

Torque τ = MB sin θ τ1 =MB1 sin 90°=MB1 τ2 = MB2 sin 90° = MB2 or (MB1/MB2)=(τ1/τ2) ∴ (B1/B2)=(τ1/τ2)

Q. Torques $τ_{1}$ and $τ_{2}$ are required for magnetic needle to remain perpendicular to the magnetic fields $B_{1}$ and $B_{2}$ at two different places. The ratio $B_{1} / B_{2}$ is

$\frac{τ _{2}}{τ _{1}}$

$\frac{τ _{1}}{τ _{2}}$

$\frac{τ _{1} + τ _{2}}{τ _{1} - τ _{2}}$

$\frac{τ _{1} - τ _{2}}{τ _{1} + τ _{2}}$

Torque $τ = MB sin θ$
$τ_{1} = M B_{1} sin 9 0^{\circ} = M B_{1}$
$τ_{2} = M B_{2} sin 9 0^{\circ} = M B_{2}$
or $\frac{M B _{1}}{M B _{2}} = \frac{τ _{1}}{τ _{2}}$
$∴ \frac{B _{1}}{B _{2}} = \frac{τ _{1}}{τ _{2}}$

Q. Torques τ1​ and τ2​ are required for magnetic needle to remain perpendicular to the magnetic fields B1​ and B2​ at two different places. The ratio B1​/B2​ is

τ1​τ2​​

τ2​τ1​​

τ1​−τ2​τ1​+τ2​​

τ1​+τ2​τ1​−τ2​​