Q. The resistance of an ammeter is 13 Ω 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
A) 2 Ω
B) 0.2 Ω
C) 2 k Ω
D) 20 Ω
Explanation
[Solution from source] The meter still carries 100 A, so the shunt carries 650 A at the same voltage: S = 13 × 100/650 = 2 Ω. 0.2 Ω would be a power-of-ten slip. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.