Question

When a rectangular coil is rotated in a uniform magnetic field about an axis passing through its centre and perpendicular to the field, the emf induced in the coil varies:

• A. Linearly
• B. Exponentially
• C. Sinusoidally
• D. None of these

Answer 1

The correct option is C Sinusoidally

$ϵ=\frac{\Delta \varphi }{\Delta t}$

$\varphi \left(\theta \right)=BAcos\left(\theta \right)$

The angle between Area and field is ${90}^o$.

$ϵ=\frac{\Delta BAcos\left(\theta \right)}{\Delta t}$

Hence it is a sinusoidal graph.