Question

How can the induced voltage from an AC generator be increased?

• A. By reversing the direction of rotation
• B. By increasing the speed of rotation.
• C. By decreasing the number of turns in the coil.
• D. By increasing the number of turns in the coil.

Answer 1

Answer: (B), (D)

By increasing the number of turns in the coil.

Emf generated in an AC generator is given by,

$E=NBA\omega$

Where, $N$ is the number of turns in the coil, $B$ is the magnetic field, $A$ is the area of the coil and $\omega$ is the angular speed of the coil.

The emf can be increased by increasing any of the above factors. Therefore, generated emf can be increased by increasing the speed of rotation and by increasing the number of turns in the coil.

While reversing the direction of rotation has no effect on the magnitude of generated emf.

Hence, options $\left(B\right)$ and $\left(D\right)$ are the correct answers.