Question

In the working of deflection magnetometer, the deflection can never be :

• A. ${90}^o$
• B. ${60}^o$
• C. ${30}^o$
• D. ${45}^o$

Answer 1

The correct option is A ${90}^o$

$\frac{M}{H}=\frac{4\pi {(d^2-l^2)}^2}{2d}\tan \theta$
$\frac{M}{H}=\frac{4\pi {(d^2+l^2)}^{3/2}}{{\mu }_0}\tan \theta$
$M=$ Magnetic Moment of the tan magnet
$d=$ distance of centre of the magnet from the carter of the magnetometer
$2l=$ the magnetic length of the Bar magnet
$\theta =$Angle of the deflection
If $\theta$ is ${90}^o$ then tan $\theta$ is infinity that implies $H=0$, which is not possible.