Question

Solve the above Problem !!!​

Answer 1

Explanation:

$\tt {n}_{1} = 50 \: \: \: \: \: \: {n}_{2} = 40 \\ \tt {\theta}_{1} = 30 \:\:\:\:\:\: {\theta}_{2} = 45 \\ \\ \tt {B}_{1} : {B}_{2} = ? \\ \\ \tt n \longrightarrow No. \: of \: vibrations \: per\:minute \\ \tt \theta \longrightarrow Angle\:of\:dip \\ \tt B \longrightarrow Magnetic\:field \\ \\ \tt We\:know\:that \\ \\ \tt n \alpha \sqrt{Bcos\theta} \\ \\ \tt \frac{{n}_{1}}{{n}_{2}} = \sqrt{\frac {{B}_{1}cos{\theta}_{1}}{{B}_{2}cos{\theta}_{2}}} \\ \\ \tt \longrightarrow \frac{50}{40} = \sqrt{\frac{{B}_{1}cos30}{{B}_{2}cos45}}\\ \\ \tt Squaring\:on\:both\:sides \\ \\ \tt \longrightarrow \frac{25}{16} = \frac{{B}_{1}}{{B}_{2}} × \frac{\sqrt{3}}{2} × \sqrt{2} \\ \\ \tt \longrightarrow \frac{{B}_{1}}{{B}_{2}} = \frac{25}{16} × \frac{\sqrt{2}}{\sqrt{3}} \\ \\ \tt \longrightarrow \boxed{\bold{\underline{\red{\tt \frac{{B}_{1}}{{B}_{2}} = \frac{25}{8\sqrt{2}}}}}}$

Answer 2

See the above answer !!!