In the circuit shown, what is the potential difference across R3? A 10 V battery connected in a single loop with three resistors in series: R1 = 2 Ω, R2 = 3 Ω and R3 = 5 Ω.

In the circuit shown, what is the potential…

In the circuit shown, what is the potential difference across R3?

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In the circuit shown, what is the potential difference across R3?

2 VCorrect answerYour answer3 VCorrect answerYour answer5 VCorrect answerYour answer10 VCorrect answerYour answer

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CorrectNot quiteAnswer C

Correct answer: C

Total resistance = 2 + 3 + 5 = 10 Ω, so the current is 10 ÷ 10 = 1 A.
The same 1 A flows through each resistor in series. V across R3 = I × R = 1 × 5 = 5 V.

Worth noting

10 V is the whole battery voltage; in series it is shared, in proportion to the resistances.

Ten questions from Everyday Physics, at your own pace.

Ten questions from Everyday Physics, at your own pace.