Physics for IGCSE & O level - Electricity (Section 11)
1
In a parallel circuit, if one branch has a resistance of 10 ohms, and another branch has a resistance of 20 ohms, which branch will have more current flowing through it?
Відповідь
(A)
The 10-ohm branch
2
How does the diameter of a wire affect its resistance?
Відповідь
(A)
Larger diameter = lower resistance
3
What is the unit of measurement for the amount of electrical charge?
Відповідь
(C)
Coulomb
4
What is the effect on the total resistance of a circuit if a parallel branch is added with a very high resistance?
Відповідь
(C)
The total resistance stays almost the same.
5
What is the function of an LED?
Відповідь
(B)
To produce light when current flows through it
6
In a series circuit, where are the components connected?
Відповідь
(B)
one after the other in a single path
7
What happens to the current if the voltage increases while the resistance stays constant?
Відповідь
(B)
The current increases.
8
Which items are described as conductors?
Відповідь
A
B
C
9
What is the term for the opposition to the flow of current in an electrical circuit?
Відповідь
(C)
Resistance
10
What is the equivalent resistance of two 2-ohm resistors in series?
Відповідь
(D)
4 ohms
11
Which of the following electrical hazards can cause serious injury or death?
Відповідь
A
B
C
12
In a parallel circuit, if one resistor breaks, what happens to the other resistors?
Відповідь
(C)
They continue to function.
13
What does the letter "I" represent in electrical circuits?
Відповідь
(A)
Current
14
What type of current does a battery typically supply?
Відповідь
(B)
Direct Current (DC)
15
What should you do if a wireless appliance electrocutes someone?
Відповідь
(C)
Pull the plug if it is safe to do so, and call for help.
16
What happens when the filament temperature increases?
Відповідь
(A)
Resistance increases
17
What is the unit for measuring electrical frequency?
Відповідь
(C)
Hertz
18
What is the purpose of a step-down transformer?
Відповідь
(B)
To decrease the voltage
19
Which type of resistor is affected by the amount of light shining on it?
Відповідь
(C)
Light Dependent Resistor
20
Which of the following is a good conductor of electricity?
Відповідь
(C)
Copper
21
What unit is used to measure electrical energy?
Відповідь
(C)
Joule
22
Which materials would be considered as insulators?
Відповідь
(C)
Rubber
23
What kind of current is used in the main electrical grid?
Відповідь
(B)
Alternating current
24
What happens if you add more resistors in series?
Відповідь
(C)
The overall resistance increases.
25
What flows through a wire to make an electric circuit work?
Відповідь
(A)
Electrons
26
If two equal resistors are connected in parallel, the equivalent resistance is:
Відповідь
(C)
Half the value of a single resistor
27
How is electrical power calculated?
Відповідь
(A)
P = V x I
28
In a parallel circuit, how is the total current related to the current in each branch?
Відповідь
(B)
The total current is the sum of the branch currents.
29
If a device uses 100 watts of power and is connected to a 230V supply, what is the current?
Відповідь
(A)
0.43 A
30
Which type of energy is typically transformed by a light bulb?
Відповідь
(B)
Electrical to light and heat
31
What is the name of the law that relates voltage, current, and resistance?
Відповідь
(B)
Ohm's Law
32
How does the cross-sectional area of a conductor affect its resistance?
Відповідь
(B)
Smaller area means higher resistance
33
What is the frequency of the mains electricity in most countries?
Відповідь
(A)
50 Hz
34
What type of material has more resistance?
Відповідь
(B)
Nichrome
35
If two resistors (R1 and R2) are in parallel, what happens to the current in each resistor?
Відповідь
A
D
36
In a parallel circuit, how is the total current calculated?
Відповідь
(C)
By summing the individual currents in each branch.
37
What formula is associated with Ohm's Law?
Відповідь
(B)
V = IR
38
What is the relationship between potential difference and current in a metallic conductor at constant temperature?
Відповідь
(A)
Directly proportional
39
If a 12V battery is connected to a 6-ohm resistor, what is the current flowing through the resistor?
Відповідь
(B)
6 Amps
40
Which of these is NOT a common electrical hazard?
Відповідь
(D)
Magnetic fields
41
What is the purpose of a light bulb filament?
Відповідь
(C)
To produce light
42
What is the combined resistance of 10, 20, and 30 ohms resistors in series?
Відповідь
(A)
60 ohms
43
What is the SI unit of electric charge?
Відповідь
(D)
Coulomb
44
What is the formula for Ohm's Law?
Відповідь
(C)
V = I * R
45
What is the unit of measurement for electrical power?
Відповідь
(D)
Watt
46
What is the primary function of an ammeter in a circuit?
Відповідь
(B)
To measure current
47
If two resistors are connected in parallel with equal resistances, the current will be:
Відповідь
(A)
The same through both resistors
48
What happens to the current in a parallel circuit when a bulb burns out?
Відповідь
(C)
The total current remains the same.
49
Which of the following is a unit of electrical power?
