$CATEGORY: Science - Khan Academy/13.Magnetic Effect of electric current/13.Magnetic Effect of electric current--Electric generator

//Multiple Choice

An electric generator works on the principle of\:
{
=Electromagnetic induction
~Electric motor effect
~Electrostatic force
~Thermal expansion
}

In a D.C. generator, the current is\:
{
=Unidirectional
~Alternating
~Constantly reversing
~Bidirectional
}

The function of the slip rings in an A.C. generator is to\:
{
=Maintain continuous contact with the external circuit
~Change the direction of current
~Reverse the polarity of the generator
~Provide insulation between the armature and the external circuit
}

In an A.C. generator, the frequency of the generated current depends on\:
{
=All of the above
~The speed of rotation of the coil
~The strength of the magnetic field
~The number of turns in the coil
}

The part of a D.C. generator that converts alternating current to direct current is\:
{
=Commutator
~Slip rings
~Brushes
~Armature
}

//True or False

In an A.C. generator, the direction of the current remains the same. {F}

A D.C. generator uses a split-ring commutator to produce unidirectional current. {T}

Slip rings in a D.C. generator are used to reverse the current direction. {F}

The energy conversion in an electric generator is from electrical energy to mechanical energy. {F}

The induced voltage in a generator is directly proportional to the speed of the rotating coil. {T}

//Fill in the blanks



//Numericals



//Match the following

Match the following items from Column A with their correct corresponding options from Column B\:
{
= Armature -> Rotating coil in a generator 
= Slip rings -> Used in A.C. generator to maintain contact 
= Commutator -> Part of D.C. generator 
= A.C. Generator -> Produces unidirectional current 
= Electric Generator -> Converts mechanical energy to electrical energy 
}


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