A circuit with a 10 V battery and three resistors (2 Ω, 3 Ω, 5 Ω) in series is shunted by a 4 Ω resistor across the 3 Ω resistor. The current through the 4 Ω resistor is:
Correct answer: A. 0.5 A
- A. 0.5 A
- B. 1 A
- C. 1.5 A
- D. 2 A
Explanation
Series resistance without shunt = 2 + 3 + 5 = 10 Ω. With 4 Ω shunting 3 Ω, the equivalent resistance of parallel = (3 × 4)/(3 + 4) = 12/7 Ω. Total resistance = 2 + 12/7 + 5 = 61/7 Ω. Total current I = 10/(61/7) = 70/61 A. Voltage across parallel = (70/61) × (12/7) ≈ 2 V. Current through 4 Ω = 2/4 = 0.5 A.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Current Electricity
Steady current relates charge flow to potential difference, resistance and resistivity, including how temperature changes a conductor's resistance. Sources with internal resistance have terminal voltage below their emf when delivering current, and maximum power output occurs under a specific load condition rather than at zero resistance.
Practise Current Electricity
1,052 free Current Electricity MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Current Electricity questions
A 100 Ω resistor is connected to a 220 V supply. If a second identical resistor is added in series, the total power consumed is:
Two cells (E₁ = 6 V, r₁ = 1 Ω; E₂ = 4 V, r₂ = 1 Ω) are connected in parallel to a 5 Ω resistor. The equivalent emf of the combination is:
A circuit has three resistors: 4 Ω and 8 Ω in parallel, connected in series with a 6 Ω resistor and a 12 V battery. The power dissipated in the 6 Ω resistor is:
A wire of resistance R is bent into a square, and a battery is connected across one side. The equivalent resistance across adjacent corners is:
A circuit consists of a 15 V battery with internal resistance 2 Ω connected to two parallel branches: one with 4 Ω and 6 Ω in series, and the other with 8 Ω. The total current supplied by the battery is:
A wire of resistance 24 Ω is cut into three equal parts, and all parts are connected in parallel. The equivalent resistance is: