When a cell of e.m.f 3.06V is connected, the balance of a potentiometer is 75cm, Calculate the new balance of a cell of e.m.f 2.295V
-
56.26cm
- 73.20cm
- 77.80cm
- 78.70cm
The correct answer is: A
Explanation
The balance length of a potentiometer is directly proportional to the e.m.f
Thus, \(\frac{L_1}{L_2} = \frac{E_1}{E_2}\)
\(L_2 = L_1\times \frac{E_2}{E_1}\)
\(L_2 = 75 \times \frac{2.295}{3.06}\)
= 75 x 0.750 = 56.25cm
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