Current Electricity Practice Questions
Class 12 · Physics · 1806 free MCQs with instant results and detailed explanations.
1806
Total
610
Easy
850
Medium
346
Hard
Start Practicing Current Electricity
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Topics in Current Electricity
Meter Bridge
467
Kirchhoff's Laws
427
Ohm's Law
378
Wheatstone Bridge
534
Sample Questions from Current Electricity
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
Which of the following statements correctly describes Ohm's Law?
A.
The current through a conductor is directly proportional to the voltage across it.
B.
The resistance in a circuit is equal to the voltage divided by the current.
C.
Power is directly proportional to the product of current and resistance.
D.
Voltage is inversely proportional to the resistance in a circuit.
Show Answer & Explanation
Correct Answer: A
Ohm's Law states that the current (I) through a conductor between two points is directly proportional to the voltage (V) across the two points, provided the temperature remains constant.
Q2
Easy
If a resistor of 4 ohms is connected across a 12V battery, what is the current flowing through the resistor?
A.
3A
B.
4A
C.
2A
D.
1A
Show Answer & Explanation
Correct Answer: C
According to Ohm's Law, the current (I) can be calculated using the formula I = V/R. Here, V = 12V and R = 4 ohms, so I = 12V / 4ฮฉ = 3A.
Q3
Easy
A material obeys Ohm's Law. If the voltage across it is doubled, what happens to the current flowing through it?
A.
It remains the same.
B.
It doubles.
C.
It is halved.
D.
It quadruples.
Show Answer & Explanation
Correct Answer: B
For a material that obeys Ohm's Law, the current is directly proportional to the voltage. If the voltage is doubled, the current also doubles.
Q4
Medium
What is the mathematical representation of Ohm's Law?
A.
V = IR
B.
P = IV
C.
R = V/I
D.
I = V/R
Show Answer & Explanation
Correct Answer: A
Ohm's Law states that the voltage (V) across a conductor is directly proportional to the current (I) flowing through it, with resistance (R) as the proportionality constant.
Q5
Medium
Which of the following statements is true regarding Ohm's Law?
A.
It applies to all materials without exception.
B.
It is applicable only to superconductors.
C.
It applies to linear resistors under normal conditions.
D.
It states that resistance is independent of temperature.
Show Answer & Explanation
Correct Answer: C
Ohm's Law applies to linear resistors that maintain a constant resistance irrespective of the voltage and current, under normal conditions.
Q6
Medium
If the resistance in a circuit doubles, what happens to the current if the voltage remains constant?
A.
It doubles.
B.
It halves.
C.
It remains the same.
D.
It quadruples.
Show Answer & Explanation
Correct Answer: B
According to Ohm's Law, if resistance increases while voltage remains constant, current decreases; specifically, it will halve if resistance doubles.
Q7
Medium
In a circuit with a voltage of 24 V and a total resistance of 6 ohms, what is the total current flowing through the circuit?
A.
4 A
B.
6 A
C.
8 A
D.
2 A
Show Answer & Explanation
Correct Answer: A
Using Ohm's Law, I = V/R = 24 V / 6 ohms = 4 A.
Q8
Hard
If the resistance of a conductor is doubled while keeping the voltage constant, what happens to the current flowing through it?
A.
It doubles
B.
It stays the same
C.
It halves
D.
It quadruples
Show Answer & Explanation
Correct Answer: C
According to Ohm's Law, if resistance increases while voltage remains constant, the current decreases. Specifically, if R is doubled, I = V/(2R) = I/2.
Q9
Hard
If a metal wire is stretched to increase its length, how does this affect its resistance?
A.
Resistance decreases
B.
Resistance remains the same
C.
Resistance increases
D.
Resistance becomes zero
Show Answer & Explanation
Correct Answer: C
When a wire is stretched, its length increases and cross-sectional area decreases, resulting in increased resistance as R = ฯ(L/A).
Q10
Hard
An electric bulb operates at a voltage of 220V and has a resistance of 110 ohms. What is the power consumed by the bulb?
A.
400 W
B.
220 W
C.
110 W
D.
440 W
Show Answer & Explanation
Correct Answer: A
Power can be calculated using the formula P = V^2/R. Thus, P = (220^2) / 110 = 48400 / 110 = 400 W.
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Current Electricity โ Class 12 Physics Practice Questions Online
This page contains 1806 practice MCQs for the chapter Current Electricity in Class 12 Physics. The questions are organized by difficulty โ 610 easy, 850 medium, 346 hard โ so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit. This chapter covers 4 topics, giving you comprehensive coverage of the entire chapter.