Phy Y11 C21 AC Generator _ Electromagnetic Induction 01

What is the name of the rectangle shape component of the AC generator?

• wire

• Armature

• Rectangle bar

• spindle

The armature can rotate by

• the flow of sound

• the flow of water

• the flow of wind

• pressurised steam

The two metal rings that connect to the armature are called

• split rings

• slip rings

• diamone rings

• golden rings

The brushes connected to the rings are made of

• cotton

• magnesium

• carbon

• aluminium

What is the function of the brushes in an AC generator?

• Control voltage output

• Generate heat

• Store electrical energy

• Transfer electrical current

How is contact between the coil and circuit maintained in an AC generator?

• 
  It cannot be maintained.

• A split ring commutator connects to each side for half a turn

• Slip rings and brushes allow continuous connection

• The alternator can only complete one revolution and must then be rotated in reverse

The working principle og AC generator is

• Electro motive force 

• Electromagnetic induction 

• generator energy conversion 

• induced voltage

If the coil is placed perpendicular to field lines then the number of lines passing through the coil is:

• Zero

• Minimum

• Maximum

• May be maximum or minimum

The direction of induced emf or current is indicated by:

• Fleming’s left-hand rule

• Fleming’s right-hand rule

• Faraday’s law of electromagnetic induction

• Ampere’s swimming rule

When a coil is held half a cycle in magnetic field, the induced current in it is :

• becomes maximum

• randomly changes

• continuously changes

• zero