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Physics for IGCSE & O level - Electricity (Section 10)

1
Which of the following formulas can be used to calculate combined resistance of two resistors in parallel?
Answer
(C)
1/R = 1/R1 + 1/R2
2
Which component in a circuit resists the flow of electrons?
Answer
(B)
Resistor
3
In a parallel circuit, if one branch is open (broken), what happens to the other branches?
Answer
(B)
They continue to function.
4
Which of these materials is a semiconductor?
Answer
(C)
Silicon
5
If the resistance in a circuit increases, what happens to the current (assuming voltage remains constant)?
Answer
(A)
The current decreases.
6
What happens to the current in a series circuit if you increase the resistance?
Answer
(B)
The current decreases
7
What happens when resistors are in parallel?
Answer
(B)
The current divides.
8
If the diameter of a wire is increased, what happens to its resistance, assuming length and material remain the same?
Answer
(B)
Resistance decreases.
9
If you increase the voltage across a fixed resistor, what happens to the current?
Answer
(A)
The current increases
10
Which of the following would typically be found in a household circuit?
Answer
A
B
C
11
Which of these is a safety measure for a UK plug?
Answer
A
C
12
What type of component is commonly used to step up or step down voltage?
Answer
(D)
A transformer
13
Which of the following are measured in amperes?
Answer
(A)
Electric current
14
Which safety device protects against the risk of electrocution?
Answer
(C)
Earth (grounded) wire
15
What safety device is designed to immediately cut off the power in the event of a fault?
Answer
(C)
Circuit breaker
16
What does a light-dependent resistor (LDR) do?
Answer
(B)
Varies resistance based on light.
17
Which quantity is measured in watts?
Answer
(C)
Power
18
Which of these has a high resistance?
Answer
(B)
A thin wire
19
If you have a 12V battery and two 6-ohm resistors in series, what is the total resistance?
Answer
(C)
12 ohms
20
Which of the following materials would likely be the *least* resistant conductor?
Answer
(B)
Copper
21
What is the purpose of a fuse in an electrical circuit?
Answer
(C)
To prevent overcurrent.
22
Which wire in a standard UK three-pin plug is used to connect the appliance to the earth?
Answer
(C)
Earth
23
In a parallel circuit, what happens if one branch is open (broken)?
Answer
(D)
The other branches continue to function.
24
Which of the following is measured in Volts?
Answer
(C)
Voltage
25
What is the relationship between the voltage, current, and resistance (Ohm's Law)?
Answer
(C)
Voltage = Current * Resistance
26
How do electrons move in a conductor when connected in a circuit?
Answer
(C)
Towards the positive terminal
27
What does LED stand for?
Answer
(A)
Light Emitting Diode
28
Which factors affect the resistance of a wire?
Answer
A
B
C
29
In series circuits, how does the current compare across the components?
Answer
(B)
The same for each component
30
What is the formula for Ohm's Law?
Answer
(A)
V = IR
31
What type of resistor is affected by light?
Answer
(D)
Light-dependent resistor
32
What is the purpose of a switch in a circuit?
Answer
(C)
To control the flow of current
33
Which of the following components is a semiconductor device?
Answer
(C)
Diode
34
Which factors affect the force between charges?
Answer
A
B
35
Which of the following is a source of electrical energy?
Answer
A
B
C
36
Which of the following components is designed to provide a specific amount of resistance?
Answer
(B)
Resistor
37
How is the current measured in a circuit?
Answer
(C)
Using an ammeter in series.
38
What is the relationship between charge, current, and time?
Answer
(A)
Charge = Current x Time
39
Which of the following formulas represents the electrical power equation?
Answer
(A)
P = V x I
40
If the voltage in a circuit is doubled, what happens to the current (assuming resistance remains constant)?
Answer
(B)
The current is doubled
41
What kind of relationship is there between the resistance and the area?
Answer
(B)
Indirectly proportional
42
What is the role of the earth wire in a household electrical system?
Answer
(B)
To provide a low-resistance path to ground
43
What happens to the resistance of a metallic conductor as its temperature decreases?
Answer
(B)
Decreases
44
What is the effect of having more cells (batteries) connected in series?
Answer
(B)
Increased voltage
45
What type of resistor has a resistance that decreases when light shines on it?
Answer
(C)
Light Dependent Resistor
46
Which of the following is a good conductor of electricity?
Answer
(C)
Copper
47
What is the relationship between the resistance and the material of the conductor?
Answer
(A)
Directly Proportional
48
What are the parts of atom?
Answer
A
B
C
49
What does the symbol 'V' stand for in the context of electricity?
Answer
(A)
Volt
50
In a series circuit, what is the total resistance equal to?
Answer
(A)
The sum of the individual resistances