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