Lakhmir Singh and Manjit Kaur Solutions for Chapter: Magnetic Effect of Electric Current, Exercise 20: Multiple Choice Questions (MCQs)

A rectangular coil of copper wire is rotated in a magnetic field. The direction of induced current changes once in each:

The device used for producing electric current is called a:

The essential difference between an AC generator and a DC generator is that:

When the switch S is closed in the figure given below, the pointer of the galvanometer moves to the right.

If S is kept closed, the pointer will:

Each one of the following changes will increase emf (or voltage) in a simple generator except:

The north pole of a long bar magnet was pushed slowly into a short solenoid connected to a galvanometer. The magnet was held stationary for a few seconds with the north pole in the middle of the solenoid and then withdrawn rapidly. The maximum deflection of the galvanometer was observed when the magnet was:

The frequency of direct current (d.c.) is:

The frequency of alternating current (a.c.) supply in India is: