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In a meter-bridge experiment to find an unknown resistance S, the balance (null) point D is found 30 cm from the left end. If the known resistance R = 5.6 kohm is in the left gap, what is the value of S?

2400 Ω
240 Ω
24 Ω
2.4 Ω

Correct answer: 2400 Ω

Solution

At balance the ratio of gap resistances equals the ratio of the corresponding wire lengths.

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