Physics for IGCSE & O level - Electricity (Section 8)
1
What does the 'live' wire do in an electrical circuit?
Odpowiedź(B)
Carries the current from the source
2
What is the unit of measurement for electrical potential difference (voltage)?
3
What unit is commonly used to measure the frequency of AC electricity?
4
What are the basic components of an electrical circuit?
5
What is the formula for calculating power (P) using voltage (V) and current (I)?
6
What unit is used to measure potential difference?
7
Which of the following components is designed to limit current?
8
Which of the following is a property of parallel circuits?
Odpowiedź(B)
Voltage is the same across all components
9
What happens to the current if the voltage is kept constant, and the resistance is halved?
10
What is the unit of measurement for electrical resistance?
11
If the length of a wire is reduced to a quarter of its original length, how does the resistance change?
12
What happens to the brightness of a lamp if the current flowing through it increases?
13
In a series circuit, what happens to the voltage drop across each resistor?
Odpowiedź(B)
The voltage drop is proportional to the resistance.
14
What is the combined resistance of resistors in series?
15
What is the purpose of a fuse in an electrical circuit?
Odpowiedź(C)
To protect the circuit from overcurrent.
16
What does the term 'current' refer to in an electrical circuit?
Odpowiedź(B)
The rate of flow of electric charge
17
Which of the following can be charged by rubbing?
18
What type of electrical current flows in one direction only?
19
What is the relationship between voltage, current, and resistance (Ohm's Law)?
Odpowiedź(C)
Voltage is directly proportional to both current and resistance
20
If the current is kept constant, how does doubling the resistance affect the voltage?
21
Which unit measures the rate of electrical energy transfer?
22
What is the SI unit for power?
23
If the voltage across a 4-ohm resistor is 12 volts, what is the current flowing through it?
24
What is the purpose of a ground wire in an electrical circuit?
Odpowiedź(B)
To protect against electric shock.
25
What type of circuit has all of its components connected along a single path?
26
If a copper wire has twice the diameter of another copper wire, what is the relationship between their resistances?
Odpowiedź(A)
The resistance of the wider wire is half.
27
What materials are used in electrostatic precipitators?
28
Which statement is true about the current in a series circuit?
Odpowiedź(C)
The current is the same at all points.
29
Which of the following can cause an object to be charged?
30
What does a voltmeter measure?
Odpowiedź(B)
Voltage (Potential Difference)
31
If two resistors are connected in series and have values of 10 ohms and 20 ohms, what is the total resistance?
32
What is the purpose of a potential divider?
33
What is the unit for resistance?
34
What is the formula for calculating power (P) given voltage (V) and current (I)?
35
What component is used to increase or decrease AC voltage?
36
What are the units used to measure electrical resistance?
37
What is the difference between a series and a parallel circuit?
Odpowiedź(A)
Only one path for the current flow vs multiple paths
38
If a 100W light bulb operates at 120V, what is the current draw?
39
If the resistance in a circuit is increased and the voltage remains constant, what happens to the current?
40
What can a charged object do to an uncharged object?
41
What are the dangers of touching electrical wires?
42
What is the relationship between voltage and current in a circuit, according to Ohm's law?
43
If a 10-ohm resistor and a 20-ohm resistor are connected in parallel, which statement is correct?
Odpowiedź(B)
The current through the 20-ohm resistor is less.
44
What is the name of the part of atom with negative charge?
45
Which of these is a common use for a reed switch?
Odpowiedź(B)
Detecting the presence of a magnet
46
What charge is associated with the neutrons?
47
What are the advantages of using a parallel circuit?
48
What is the role of a step-up transformer?
49
Which component in an electrical circuit converts electrical energy into light energy?
50
What happens if you reverse the terminals of a diode in a circuit?
