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

//Multiple Choice

The function of the commutator in a DC motor is to\:
{
=Reverse the direction of current
~Increase the speed of the motor
~Supply electric power
~Control the magnetic field
}

In an electric motor, the energy conversion takes place from\:
{
=Electrical energy to mechanical energy
~Mechanical energy to electrical energy
~Chemical energy to electrical energy
~Thermal energy to mechanical energy
}

The role of brushes in an electric motor is to\:
{
=Ensure continuous contact between the commutator and external circuit
~Convert mechanical energy into electrical energy
~Reverse the magnetic field
~Control the speed of the motor
}

The direction of force experienced by a current-carrying conductor in a magnetic field is given by\:
{
=Fleming's Left-Hand Rule
~Fleming's Right-Hand Rule
~Ampere's Law
~Faraday's Law
}

Which part of the motor rotates when the current is passed through the motor?
{
=Armature
~Brushes
~Commutator
~Stator
}

//True or False

In an electric motor, electrical energy is converted into mechanical energy. {T}

A commutator is used in an electric motor to maintain a continuous connection between the rotor and external circuit. {T}

The stator is the rotating part of an electric motor. {F}

Fleming's Right-Hand Rule determines the direction of current in an electric motor. {F}

Electric motors are used in appliances such as fans and washing machines. {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 -> Rotates when current is passed
= Commutator -> Reverses current direction in armature
= Brushes -> Provides contact between commutator and external circuit
= Fleming’s Left-Hand Rule -> Determines direction of force on conductor
= Electric motor -> Converts electrical energy to mechanical energy 
}


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