Physicshard · Past Paper
Which of the following will not change the direction of rotation of a DC motor?
AReversing battery terminals
BReversing magnetic field poles
CReversing both battery and magnetic poles
DChanging the commutator type
✓ Correct Answer: C — Reversing both battery and magnetic poles
Reversing both current and magnetic field cancels out the change in force direction (Left-hand rule).
Share this question
More from Physics
- A ray of light passes from air into a liquid. The angle of incidence is 45 and angle of refraction is 30. Find refractive index.
- What is the relationship between the velocity (v), frequency (f), and wavelength (λ) of a sound wave?
- What is the equivalent resistance between A and B in the provided circuit diagram?
- Calculate the force of attraction between two bodies of mass 1 kg each separated by 1 meter distance.
- If a force of 1 Newton moves a body by 1 meter in its own direction, the work done is: