Physics for IGCSE & O level - Electricity (Section 1)
1
Which of the following is the most common type of fuse?
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(B)
Thermal Fuse
2
What happens to the current in a circuit if the voltage is held constant and the resistance is increased?
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(B)
The current decreases.
3
What happens if the current flowing through a resistor increases?
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(C)
The power dissipated by the resistor increases.
4
If the length of a wire is doubled, what happens to its resistance (assuming other factors are constant)?
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(A)
Doubles
5
What is the purpose of the neutral wire in a three-core cable?
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(A)
To provide a path for the current to return to the source.
6
What is the unit for measuring electrical power?
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(D)
Watt
7
What is the name of the point where two or more components connect in a circuit?
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(A)
Node
8
Which of the following is a unit of electrical energy?
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(C)
Joule
9
What is the unit for measuring electrical charge?
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(C)
Coulomb
10
What does the abbreviation LED stand for?
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(A)
Light Emitting Diode
11
What is the effect of adding more resistors in series in a circuit?
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(B)
The total resistance increases.
12
If two resistors are connected in parallel, and one resistor has a resistance of 10 ohms and the other has a resistance of 20 ohms, what is the total resistance?
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(B)
6.67 ohms
13
What best describes electric charge?
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(D)
Properties
14
What is measured in units of Watts?
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(D)
Power
15
How does the length of a wire affect its resistance?
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(C)
Longer wire, higher resistance
16
What is the unit for measuring electrical energy?
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(C)
Joule
17
Which of the following would become charged by rubbing it with a dry, wool cloth?
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(A)
PVC
18
In a parallel circuit, what happens to the total resistance if you add another resistor?
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(A)
Decreases
19
What kind of materials are electrical conductors?
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(A)
Metals
20
What is the role of a double insulated appliance?
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(A)
It does not have an earth wire
21
What happens to the total resistance in a series circuit if a resistor is replaced with one of a higher resistance value?
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(A)
The total resistance increases.
22
In an electric circuit, what is the function of an inductor?
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(B)
To oppose changes in current
23
What is the relationship between current (I), voltage (V), and resistance (R) in a circuit?
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(A)
V = I * R
24
In a circuit, the battery supplies energy which is transformed to the...
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(A)
Lamp
25
What is the term for the number of times the direction of current changes per second?
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(B)
Frequency
26
What are the two types of electric charge?
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(A)
Positive and negative
27
What will happen if one of the lamps in the series circuit breaks?
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(B)
All lamps will not light
28
What type of meter is used to measure current?
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(C)
An ammeter
29
What are the advantages of arranging some circuits in series?
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B
D
30
What is the relationship between the current and voltage in a resistor, according to Ohm's law?
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(B)
They are directly proportional.
31
What happens to the brightness of a lightbulb if the voltage across it increases?
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(B)
The bulb gets brighter.
32
Which circuit setup allows the full battery potential difference (p.d.) to reach each lamp?
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(B)
Parallel
33
Which of the following is a feature of double insulation?
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(C)
Provides two layers of insulation
34
How is the resistance of a conductor calculated?
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(B)
R = V / I
35
What is the function of a transformer?
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(B)
To change the voltage of an AC supply
36
What is the function of a variable resistor?
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(B)
To change the current in the circuit.
37
Which of the following is used to step-up (increase) or step-down (decrease) voltage?
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(C)
Transformer
38
Which of the following is a non-linear circuit element?
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(C)
Diode
39
What is the equivalent resistance of two 2-ohm resistors connected in parallel?
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(A)
1 ohm
40
How is the total current related in a parallel circuit?
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(B)
The total current is the sum of the currents in each branch.
41
What is the purpose of using multiple parallel paths in a circuit?
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(C)
To provide multiple current paths
42
What safety device is designed to protect appliances from overloads and short circuits?
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(C)
Fuse
43
What does a light emitting diode (LED) do?
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(A)
Emits light when a current flows through it.
44
Which component allows current to flow in only one direction?
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(C)
Diode
45
Which of the following is a typical household appliance that uses a high current?
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(B)
An electric iron
46
Which of the following is the unit for electrical charge?
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(C)
Coulomb
47
Which component is designed to limit the current in a circuit?
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(C)
A resistor
48
Which of the following components is a passive component?
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(D)
Resistor
49
What is the purpose of a fuse in a circuit?
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(B)
To protect the circuit from overcurrent
50
What is the main function of a capacitor in a circuit?
