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WorksheetsUnderstanding AC and DC Machines
Total questions: 10
Worksheet time: 5mins
What is the primary function of a DC motor?
To convert electrical energy into mechanical energy
To convert mechanical energy into electrical energy
To store electrical energy
To regulate voltage
Which component in an AC motor is responsible for producing a rotating magnetic field?
Stator
Rotor
Commutator
Armature
What is the unit of electrical resistance?
Ampere
Volt
Ohm
Watt
In a DC machine, what is the purpose of the commutator?
To increase the current
To convert AC to DC
To reverse the direction of current
To reduce the voltage
What is the frequency of the standard AC supply in Great Britain?
50 Hz
60 Hz
100 Hz
120 Hz
Which of the following is a type of DC motor?
Synchronous motor
Induction motor
Series motor
Stepper motor
What is the formula for calculating electrical power in a DC circuit?
P=IV
P=I2R
P=V2/R
P=IR
Which of the following materials is commonly used for the core of an electromagnet in motors?
Copper
Aluminium
Iron
Plastic
What is the main advantage of using an AC motor over a DC motor?
Higher efficiency
Simpler construction
Better speed control
Lower cost
In an AC circuit, what does the term 'reactance' refer to?
Resistance to direct current
Opposition to change in current
Voltage drop across a resistor
Power loss in the circuit
