Exam-style question
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In a potential divider circuit, if the output voltage is 5V and the total voltage is 20V with resistances of 5Ω and 15Ω, what is the voltage across the 15Ω resistor?.
- A.5V
- B.10V
- C.15V
- D.20V
Model answer
What a good answer should say
- 15V
Explanation
Why this works
Using V_out = V_total * (R2 / (R1 + R2)), where V_total = 20V, R1 = 5Ω, and R2 = 15Ω. Substituting gives V_out = 20 * (15 / (5 + 15)) = 20 * (15 / 20) = 15V.
Common mistake
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