$A$ generator with a circular coil of $100$ turns of area $2 \times 10^{-2} \,m^2$ is immersed in a $0.01 \,T$ magnetic field and rotated at a frequency of $50 \,Hz$. The maximum emf which is produced during a cycle is (in $\,V$)

When a wire loop is rotated in a magnetic field,the direction of induced $emf$ changes in every

$A$ coil having $1000$ turns and an area of $0.10 \ m^2$ rotates at half a revolution per second and is placed in a uniform magnetic field of $0.01 \ T$ perpendicular to the axis of rotation of the coil. The maximum emf voltage generated in the coil is . . . . . . $V$.

$A$ rectangular coil of $300$ turns has an average area of $25\;cm \times 10\;cm.$ The coil rotates with a speed of $50\;cps$ in a uniform magnetic field of strength $4 \times 10^{-2}\;T$ about an axis perpendicular to the field. The peak value of the induced $e.m.f.$ is (in volt): (in $\pi$)

The number of turns in the coil of an $AC$ generator are $50$ and its cross-sectional area is $2.5 \ m^2$. This coil is revolving in a uniform magnetic field of strength $0.3 \ T$ with a uniform angular velocity of $60 \ rad \ s^{-1}$. The resistance of the circuit comprising the coil is $500 \ \Omega$. The maximum induced $emf$ and maximum current produced in the generator are:

Discuss the principle and construction of an $A.C.$ generator (dynamo). Derive the formula for the induced $emf$ in an $A.C.$ generator.