Question

The power of a d.c. motor can be increased:

• A. By increasing number of turns in its coil
• B. By laminating its soft iron core
• C. By increasing the strength of current flowing through it
• D. All of these

Answer 1

The correct option is D

All of these

Explanation for the correct option:
The power of d.c. motor can be increased by the following methods:

1. By increasing the cross sectional area of the coil
2. By increasing the radial magnetic field strength
3. By increasing the number of turns of the coil
4. By increasing the magnitude of current passing through the coil
5. By winding a large number of coils on the same soft iron core
6. By laminating its soft iron core

Therefore, all the given options can increase the power of a d.c. motor.

Thus D is the correct option.