Worksheets2365 602 RJH2
Total questions: 25
Worksheet time: 25mins
Name
Class
Date
1.
What is the primary purpose of a commutator in a DC motor?
a)
To reduce noise
b)
To increase efficiency
c)
To reverse the direction of current
d)
To generate magnetic fields
2.
In an AC circuit, what does the term 'reactance' refer to?
a)
Resistance to current
b)
Opposition to change in voltage
c)
Opposition to change in current
d)
Total impedance
3.
Which material is generally used for the core of a transformer?
a)
Copper
b)
Aluminium
c)
Steel
d)
Brass
4.
What is the function of a thyristor in an electrical circuit?
a)
Amplify signals
b)
Act as a switch
c)
Store energy
d)
Measure current
5.
Which law determines the direction of induced current in a conductor?
a)
Ohm's Law
b)
Ampere's Law
c)
Lenz's Law
d)
Faraday's Law
6.
What is the phase difference between voltage and current in a purely capacitive circuit?
a)
0 degrees
b)
45 degrees
c)
90 degrees
d)
180 degrees
7.
In a synchronous motor, what is 'hunting'?
a)
Sudden speed increase
b)
Oscillation around synchronous speed
c)
Constant speed operation
d)
Speed reduction
8.
How many electrons are there in the outer shell of a good conductor?
a)
1
b)
2
c)
3
d)
4
9.
What is the typical efficiency range of a modern transformer?
a)
50-60%
b)
60-70%
c)
70-80%
d)
95-98%
10.
What does the term 'power factor' represent in an electrical circuit?
a)
Voltage to current ratio
b)
Efficiency of power usage
c)
Phase difference between voltage and current
d)
Total power consumed
11.
Which type of circuit breaker is used most commonly for resistive loads in a house? air as the arc extinguishing medium?
a)
Type A circuit breaker
b)
Type B circuit breaker
c)
Type C circuit breaker
d)
Type D circuit breaker
12.
Which component is used to smooth the output in a rectifier circuit?
a)
Capacitor
b)
Inductor
c)
Resistor
d)
Transformer
13.
What is the main cause of change to reactance in an inductive circuit?
a)
High frequency
b)
High voltage
c)
Low current
d)
Low resistance
14.
What is the purpose of a zener diode in a circuit?
a)
Rectification
b)
Voltage regulation
c)
Current amplification
d)
Signal modulation
15.
In a three-phase system, what is the phase angle difference between each phase?
a)
30 degrees
b)
60 degrees
c)
90 degrees
d)
120 degrees
16.
What is the main advantage of using a digital multimeter over an analogue one?
a)
Lower cost
b)
Higher accuracy
c)
Simplicity
d)
Durability
17.
In a P-N junction diode, what is the 'depletion region'?
a)
Area with excess charge carriers
b)
Area with no charge carriers
c)
Area with high current density
d)
Area with low resistance
18.
What value is x10-3
a)
Milli
b)
Micro
c)
Nano
d)
Pico
19.
Which type of motor is commonly used in household appliances?
a)
Synchronous motor
b)
Induction motor
c)
Stepper motor
d)
Servo motor
20.
What is the primary use of an operational amplifier in a circuit?
a)
Signal amplification
b)
Voltage regulation
c)
Power conversion
d)
Current measurement
21.
In an RLC circuit, what is 'resonance'?
a)
Maximum resistance
b)
Maximum current flow
c)
Minimum impedance
d)
Minimum voltage drop
22.
What is the purpose of a fuse in an electrical circuit?
a)
To regulate voltage
b)
To limit current
c)
To store energy
d)
To convert power
23.
What does a 'step-up transformer' do?
a)
Decrease voltage
b)
Increase voltage
c)
Convert AC to DC
d)
Increase current
24.
What is 'hysteresis loss' in a magnetic material?
a)
Loss due to resistance
b)
Loss due to eddy currents
c)
Loss due to magnetic reversal
d)
Loss due to dielectric breakdown
25.
In a series-parallel circuit, how is the total resistance calculated?
a)
Sum of all resistances
b)
Reciprocal of the sum of reciprocals
c)
Product over sum
d)
Combination of series and parallel calculations
100 %
