Physics for IGCSE & O level - Electricity (Section 5)
1
What is the relationship between current and the number of parallel paths in a circuit?
إجابة
(B)
As the number of paths increases, the current increases
2
Which component is typically used to change the voltage of an AC supply?
إجابة
(C)
Transformer
3
What is a reed switch activated by?
إجابة
(C)
A magnet
4
Which of the following are correct about an appliance's power rating?
إجابة
A
B
C
5
What do charges do in a Van de Graaff generator?
إجابة
(B)
They become concentrated on the surface of a sphere
6
What are the components that constitute the basic circuit rules?
إجابة
A
B
C
7
What is the formula for calculating the total resistance of resistors in parallel?
إجابة
(B)
1/R_total = 1/R1 + 1/R2
8
Which of the following is a common example of a parallel circuit application?
إجابة
(C)
Household electrical wiring
9
In a series circuit, if one resistor has a voltage drop of 5V, and another has a voltage drop of 10V, what is the total voltage drop across both resistors?
إجابة
(C)
15V
10
Which statement best describes the role of a battery in a circuit?
إجابة
(C)
It provides the voltage (potential difference).
11
Which of the following describes a 'short circuit'?
إجابة
(B)
Low resistance and high current
12
What is the effect on the current in a circuit if the resistance is doubled while the voltage remains constant?
إجابة
(B)
Current halves
13
What is the frequency of the alternating current (AC) supply in most of Europe?
إجابة
(A)
50 Hz
14
What is the role of a live wire in a domestic electrical supply?
إجابة
(B)
It carries current to the appliance
15
What does the symbol 'Ω' represent in electrical circuits?
إجابة
(C)
Resistance
16
In a series circuit, if one component breaks, what happens to the rest of the circuit?
إجابة
(B)
The circuit stops working.
17
In a series circuit, if one component fails (breaks the circuit), what happens to the rest of the components?
إجابة
(B)
They also fail.
18
What is the unit of power?
إجابة
(C)
Watt
19
Which of the following are components of a simple circuit?
إجابة
A
B
C
D
20
If a lightbulb uses 100J of energy every second, what is its power?
إجابة
(A)
100 Watts
21
Which of the following is a symbol for a resistor?
إجابة
(D)
-///-
22
What are the parts of an atom?
إجابة
A
B
C
23
Which of the following is a source of AC electricity?
إجابة
(C)
A mains socket
24
In a circuit with a voltage source, a resistor, and a light bulb in series. If the resistance of the resistor increases, what happens to the brightness of the light bulb?
إجابة
(B)
The bulb will get dimmer.
25
How is resistance affected by material type?
إجابة
(C)
Different materials have varying resistance.
26
What is the standard voltage rating for a 3-pin plug in the UK?
إجابة
(C)
230V
27
Which of the following best describes the function of a variable resistor (rheostat)?
إجابة
(C)
To change the resistance in a circuit.
28
What happens to the overall resistance of a circuit if components are added in series?
إجابة
(B)
It increases
29
What is the purpose of the fuse in an electrical circuit?
إجابة
(C)
To break the circuit if the current exceeds a safe level.
30
What is the term for the opposition to the flow of electric current?
إجابة
(B)
Resistance
31
Which component opposes the flow of current in a circuit?
إجابة
(B)
Resistor
32
What is the unit used to measure resistance?
إجابة
(D)
Ohm
33
What is the effect of increasing the voltage in a circuit, assuming the resistance stays the same?
إجابة
(C)
The current increases
34
What component is used to block DC current and allow AC current to pass?
إجابة
(C)
Diode
35
In a parallel circuit, what is the same across all components?
إجابة
(A)
Voltage
36
Which of the following appliances is most likely to have a three-pin plug?
إجابة
(C)
A washing machine
37
If you plug a 1000W appliance into a 230V socket, how much current does it draw?
إجابة
(A)
4.35 A
38
What is a function of a fuse?
إجابة
(B)
To limit the current flow.
39
Which quantity is measured in Amperes (A)?
إجابة
(B)
Current
40
Which of the following is a unit of electrical power?
إجابة
(C)
Watt
41
What happens to the current in a series circuit if the voltage is increased and the resistance remains the same?
إجابة
(A)
The current increases
42
What are the units of voltage?
إجابة
(B)
Volts
43
What is the main purpose of an earth wire in an electrical appliance?
إجابة
(B)
To provide a path for fault current to flow to earth.
44
What is the effect of a double-insulated appliance regarding earthing?
إجابة
(B)
It does not require an earth wire.
45
What would be the consequence of a fuse having too high a current rating?
إجابة
(C)
The appliance could overheat and cause a fire.
46
Which of the following is a non-ohmic device?
إجابة
(C)
A diode
47
Which of the following factors does NOT affect the resistance of a wire?
إجابة
(D)
Weight
48
What is a key component in a simple circuit?
إجابة
(B)
Conductor
49
What happens to the current in a wire if the voltage is doubled and the resistance is halved?
