1. Direction of rotation of a coil in electric motor is determined by ?

faraday law of electromagnetic inductors

fleming’s right hand rule

fleming’s left hand rule

None of above

Answer: fleming’s left hand rule

Explanation:

Fleming’s left hand rule.


2. Which device produces the electric current ?

motor

generator

ammeter

galvanometer

Answer: generator

Explanation:


3. An electric generator actually acts as ?

a converter of energy.

an electromagnet.

a source of neat energy.

a source of electric charge.

Answer: a converter of energy.

Explanation:


4. To convert an ac generator into dc generator ?

A rectangular wire loop has to be used

Split-ring type commutator must be used

A stronger magnetic field has to be used

Slip rings and brushes must be used

Answer: Split-ring type commutator must be used

Explanation:

To convert an AC generator into DC generator the split ring type commutator are used which converts the direction of flow of induced current, in the external circuit, in the same direction throughout the complete rotation of the armature.


5. In Fleming’s right hand rule direction in induced current is given by ?

first finger

thumb

middle finger

none of these

Answer: middle finger

Explanation:


6. The frequency of direct current (DC) is ?

100 Hz

60 Hz

50 Hz

0 Hz

Answer: 0 Hz

Explanation:


7. AC generator works on the principle of ?

Joule’s law of heating

faraday’s law of electromagnetic induction.

none of the above

ohms law

Answer: faraday’s law of electromagnetic induction.

Explanation:


8. The magnetic field lines produced by a bar magnet ?

Originate from the south pole and end at its west pole

Originate from the north pole and end at its south pole

Originate from the north pole and end at its east pole

Originate from the south pole and end at its north pole

Answer: Originate from the north pole and end at its south pole

Explanation:

Magnetic field lines produced by a bar magnet originate from the north pole and end at its south pole.


9. The direction of induced current is given by ?

Left hand thumb rule.

Right hand thumb rule.

Fleming’s right hand rule.

Fleming’s left hand rule.

Answer: Fleming’s right hand rule.

Explanation:


10. Material of the core of a strong magnet is ?

steel

copper

soft iron

aluminium

Answer: soft iron

Explanation: