Question 44
Current ElectricityThe maximum permissible current through a galvanometer G of internal resistance 10Ω is 0.05A. A resistance R is used to convert G into a voltmeter with a maximum reading of 100V. Find the value of R and how it is connected to G.
- A.20,000 ohms in parallel
- B.19,990 ohms in series
- C.1990 ohms in series
- D.100 ohms in series.
Show the answer and explanation
Answer: C (1990 ohms in series)
Explanation
A voltmeter needs a large resistance in series. Total resistance = 100/0.05 = 2000 Ω, so R = 2000 − 10 = 1990 Ω in series.