Advertisements
Advertisements
Question
State the position of armature coil relative to the direction of magnetic field, in a D. C. motor when the deflecting couple acting and the coil is minimum.
Advertisements
Solution
The deflecting couple acting on the coil is minimum when the plane of the coil is normal to the direction of magnetic field.
RELATED QUESTIONS
State two ways of magnetising an iron piece?
Complete the following sentence :
On reserving the direction of current in a wire, the magnetic field produced by it gets _____.
The magnetic flux through a coil having 100 turns decreases from 5 milli weber to zero in 5 second. Calculate the e.m.f. induced in the coil.
Answer the following in short.
Name a few common appliances that use electromagnets.
Describe briefly one way of producing an induced current in a coil. State one factor that determines the magnitude of induced e.m.f.
State the purpose of the iron core.
How does a magnetic field set up by a solenoid change when strength of current in the solenoid is decreased?
Why is soft iron generally used as the core of the electromagnet?
What will be the effect on the working of an electric bell if instead of a direct current an alternating current is used?
State the factors that can increase the speed of rotation of the coil in a D.C. motor.
