JAMB - Physics (2024 - No. 56)

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 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