Question 26
Current ElectricityAn ammeter of resistance 5 Ω has a full-scale deflection when a current of 50 mA flows in it. The value of the resistor required to adapt it to measure a current of 5 A is
- A.19.80 Ω
- B.5.00 Ω
- C.0.05 Ω
- D.0.25 Ω
Show the answer and explanation
Answer: C (0.05 Ω)
Explanation
A shunt in parallel must carry 5 − 0.05 = 4.95 A with the same p.d. as the meter: 0.05 × 5 = 4.95 × S, so S ≈ 0.05 Ω.