Topic: Engineering Mathematics
Resistance of a given wire is obtained by measuring the current flowing in it and the voltage difference applied across it. If the percentage errors in the measurement of the current and the voltage difference are 3% each, then error in the value of resistance of the wire is
- A. 8%
- B. 6%
- C. 9%
- D. 10%
Answer: B. 6%
Explanation: From Ohm's law, V = IR, which gives R = V / I. When differentiating and dividing by V = IR to find relative errors, the maximum percentage error in resistance is the sum of the percentage errors in voltage and current: (dR/R) * 100 = (dV/V) * 100 + (dI/I) * 100. Given both are 3%, the total error in resistance is 3% + 3% = 6%.