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