The resistance of an ammeter is 13Ω and its scale is graduated for a current upto 100 amps. After an additional shunt has been connected to this ammeter it becomes possible to measure currents upto 750 amperes by this meter. The value of shunt-resistance is

Options

(a) 2Ω
(b) 0.2Ω
(c) 2 kΩ
(d) 20Ω

Correct Answer:

2Ω

Explanation:

We know, I / Is = 1 + G / S
750 / 100 = 1 + 13/S
S = 2Ω