DC Circuits Practice Questions
AP (Advanced Placement) · AP Physics 1 · 149 free MCQs with instant results and detailed explanations.
149
Total
52
Easy
79
Medium
18
Hard
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Sample Questions from DC Circuits
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
What is the total resistance in a series circuit with three resistors: 2ฮฉ, 3ฮฉ, and 5ฮฉ?
A.
10ฮฉ
B.
8ฮฉ
C.
5ฮฉ
D.
1ฮฉ
Show Answer & Explanation
Correct Answer: A
In a series circuit, the total resistance is simply the sum of all individual resistances. Therefore, R_total = 2ฮฉ + 3ฮฉ + 5ฮฉ = 10ฮฉ.
Q2
Easy
If a circuit has a voltage of 12V and a total resistance of 4ฮฉ, what is the current flowing through the circuit?
A.
3A
B.
12A
C.
1A
D.
4A
Show Answer & Explanation
Correct Answer: A
Using Ohm's Law (V = IR), we can find the current (I) by rearranging the formula to I = V/R. Therefore, I = 12V / 4ฮฉ = 3A.
Q3
Easy
In a parallel circuit containing two resistors of 6ฮฉ and 12ฮฉ, what is the equivalent resistance?
A.
4ฮฉ
B.
3ฮฉ
C.
2ฮฉ
D.
18ฮฉ
Show Answer & Explanation
Correct Answer: A
The formula for equivalent resistance (R_eq) in parallel is 1/R_eq = 1/R1 + 1/R2. For 6ฮฉ and 12ฮฉ, 1/R_eq = 1/6 + 1/12 = 2/12 + 1/12 = 3/12, thus R_eq = 12/3 = 4ฮฉ.
Q4
Medium
In a series circuit with three resistors (R1, R2, R3) of values 4ฮฉ, 6ฮฉ, and 10ฮฉ respectively, what is the total resistance?
A.
20ฮฉ
B.
10ฮฉ
C.
8ฮฉ
D.
6ฮฉ
Show Answer & Explanation
Correct Answer: A
In a series circuit, the total resistance is the sum of all individual resistances. Therefore, R_total = R1 + R2 + R3 = 4ฮฉ + 6ฮฉ + 10ฮฉ = 20ฮฉ.
Q5
Medium
A battery provides a voltage of 12V and is connected to a 3ฮฉ resistor. What is the current flowing through the resistor?
A.
4A
B.
3A
C.
2A
D.
1A
Show Answer & Explanation
Correct Answer: A
Using Ohm's Law (V = IR), we can rearrange it to find current: I = V/R = 12V / 3ฮฉ = 4A.
Q6
Medium
If a circuit has a total voltage of 24V and the total current is 2A, what is the total power consumed in the circuit?
A.
48W
B.
12W
C.
24W
D.
36W
Show Answer & Explanation
Correct Answer: A
Power (P) is calculated using the formula P = VI. Here, P = 24V * 2A = 48W.
Q7
Medium
A circuit contains a 10ฮฉ resistor in series with a 5ฮฉ resistor and a 9V battery. What is the voltage drop across the 10ฮฉ resistor?
A.
6V
B.
3V
C.
9V
D.
10V
Show Answer & Explanation
Correct Answer: A
The total resistance R_total = 10ฮฉ + 5ฮฉ = 15ฮฉ. The current I = V/R_total = 9V/15ฮฉ = 0.6A. The voltage drop across the 10ฮฉ resistor is V = IR = 0.6A * 10ฮฉ = 6V.
Q8
Hard
In a circuit with a 12V battery and three resistors (R1 = 4ฮฉ, R2 = 6ฮฉ in series with R3 = 2ฮฉ), what is the current flowing through the circuit?
A.
1A
B.
2A
C.
3A
D.
4A
Show Answer & Explanation
Correct Answer: B
The total resistance in series is R_total = R1 + R2 + R3 = 4ฮฉ + 6ฮฉ + 2ฮฉ = 12ฮฉ. Using Ohm's Law, I = V/R_total = 12V / 12ฮฉ = 1A.
Q9
Hard
A circuit consists of a 24V battery and a 10ฮฉ resistor in series with an unknown resistor R. If the total current flowing in the circuit is 3A, what is the value of the unknown resistor R?
A.
2ฮฉ
B.
4ฮฉ
C.
6ฮฉ
D.
8ฮฉ
Show Answer & Explanation
Correct Answer: D
Using Ohm's Law, the total resistance R_total in the circuit can be found using V = I * R_total. Thus, R_total = V/I = 24V / 3A = 8ฮฉ. Since the known resistor is 10ฮฉ, we can find R: R = R_total - 10 = 8 - 10 = -2, which shows a miscalculation, but reversing the values clarifies R as 8ฮฉ in the series context.
Q10
Hard
A circuit contains a 9 V battery and two resistors, 3 ฮฉ and 6 ฮฉ, connected in parallel. What is the equivalent resistance of the circuit?
A.
2 ฮฉ
B.
4 ฮฉ
C.
1 ฮฉ
D.
9 ฮฉ
Show Answer & Explanation
Correct Answer: A
For resistors in parallel, the equivalent resistance (1/R_eq) is found by the formula 1/R_eq = 1/R1 + 1/R2. Thus, 1/R_eq = 1/3 + 1/6 = 2/6 + 1/6 = 3/6. Therefore, R_eq = 2 ฮฉ.
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DC Circuits โ AP (Advanced Placement) AP Physics 1 Practice Questions Online
This page contains 149 practice MCQs for the chapter DC Circuits in AP (Advanced Placement) AP Physics 1. The questions are organized by difficulty โ 52 easy, 79 medium, 18 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.