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Physics for IGCSE & O level - Electricity (Section 12)

1
What is the name of the device used to detect the presence of electric charge?
Answer
(C)
Electroscope
2
What is the main purpose of a fuse in an electrical circuit?
Answer
(C)
To break the circuit if the current is too high
3
What happens to the total resistance of a circuit if you add more resistors in parallel?
Answer
(B)
It decreases.
4
What does the letter "V" represent in electrical circuits?
Answer
(B)
Voltage
5
If a wire has a large cross-sectional area, what can be said about its resistance?
Answer
(B)
It has low resistance.
6
What are the factors that affect resistance?
Answer
A
B
C
D
7
What type of current is used to power most of our homes?
Answer
(B)
Alternating Current (AC)
8
In a parallel circuit, which of the following is true?
Answer
A
C
9
What is the combined resistance of two 10-ohm resistors in parallel?
Answer
(A)
5 ohms
10
If you add more resistors in series, how does the total resistance change?
Answer
(A)
Increases
11
What is the main advantage of double insulation?
Answer
(B)
Provides an extra layer of protection against electric shock
12
What should be checked when a wireless appliance is electrocuted?
Answer
B
C
13
If two 10-ohm resistors are connected in series, what is the total resistance?
Answer
(C)
20 ohms
14
Which of the following is related to 'electrostatic charge'?
Answer
B
D
15
In the circuit shown on the right, what is the total current?
Answer
(D)
4.6 A
16
If you connect more bulbs in series, will the total brightness increase, decrease, or stay the same?
Answer
(B)
Decrease
17
How does adding more resistors in series affect the total resistance?
Answer
(A)
Increases it
18
What does a series circuit and a parallel circuit have in common?
Answer
B
C
19
What is the relationship between resistance and the cross-sectional area of a conductor?
Answer
(B)
They are inversely proportional.
20
What is the combined resistance of two resistors in series with the values of 5 ohms and 10 ohms?
Answer
(D)
15 ohms
21
Which type of electrical current changes direction periodically?
Answer
(B)
Alternating Current (AC)
22
A diode allows current to flow easily in one direction, but with very high resistance in the opposite direction. What is a common use of a diode?
Answer
(B)
To convert AC to DC
23
What is the total resistance of two resistors (6 ohms and 12 ohms) connected in series?
Answer
(D)
18 ohms
24
What can happen if a current is too high in a wire?
Answer
A
B
C
D
25
What type of circuit is used in domestic wiring?
Answer
(B)
Parallel circuit
26
What is the relationship between power, current, and voltage?
Answer
(C)
Power = Voltage * Current
27
In a series circuit, if the voltage is 10V and the resistance is 2 Ohms, what is the current?
Answer
(A)
5 Amps
28
If two 6-ohm resistors are connected in parallel, what is the total resistance?
Answer
(A)
3 ohms
29
How does the total resistance change if a resistor is removed from a series circuit?
Answer
(B)
Decreases
30
What is the main function of a fuse in a circuit?
Answer
(B)
To limit the current
31
What happens to the resistance of a wire as its temperature increases?
Answer
(A)
Increases
32
What does the term 'p.d.' stand for in the context of electricity?
Answer
(B)
Potential difference
33
How are the lines in an electric field shown?
Answer
(C)
Lines that always point away from positive charges and towards negative charges
34
What type of circuit is this? Resistor - Resistor - Resistor.
Answer
(A)
Series
35
What would happen to the total resistance of a circuit if you added a component with very low resistance in parallel to the circuit?
Answer
(B)
The total resistance would decrease substantially
36
What are some of the effects that a build up of static charge can cause?
Answer
(D)
All of the above
37
In a series circuit, if one bulb burns out, what happens to the other bulbs?
Answer
(B)
They go out
38
Which safety device is designed to protect against electric shock by quickly disconnecting the power?
Answer
(B)
Circuit breaker
39
What is the purpose of the filament in a light bulb?
Answer
(B)
To emit light when heated by the electric current.
40
What is the purpose of a capacitor in an electrical circuit?
Answer
(B)
To store electrical energy.
41
In a circuit, if the current is 2 amps and the resistance is 4 ohms, what is the voltage?
Answer
(D)
8 Volts
42
In a circuit, what is the relationship between voltage and current when resistance is constant?
Answer
(B)
Voltage and current are directly proportional.
43
Which of the following is a safety device designed to interrupt the flow of current in case of a ground fault?
Answer
(C)
RCD (Residual Current Device)
44
What type of circuit will continue to function even if one light bulb burns out?
Answer
(B)
Parallel circuit
45
What is the main difference between a series and parallel circuit?
Answer
(B)
Series circuits have only one path, while parallel circuits have multiple paths.
46
What is the unit used to measure current in a circuit?
Answer
(B)
Ampere
47
What is the purpose of a transformer?
Answer
(C)
To change the voltage of an AC supply
48
Which of the following are components of a typical electric circuit?
Answer
A
B
C
D
49
What does a battery do in a simple circuit?
Answer
(A)
Provides a potential difference
50
What can induce a charge?
Answer
A
D