Question

A resistor of 10 kΩ with the tolerance of 5% is connected in series with 5 kΩ resistors of 10% tolerance. What is the tolerance limit for a series network?

(a) 9%

(b) 12.04%

(c) 8.67%

(d) 6.67%

Answer 1

The correct option is (d) 6.67%

Easiest explanation: Error in 10 kΩ resistance = 10 × \(\frac{5}{100}\) = 0.5 kΩ

Error in 5 kΩ resistance = 5 × \(\frac{10}{100}\) = 5 kΩ

Total measurement resistance = 10 + 0.5 + 5 + 0.5 = 16 kΩ

Original resistance = 10 + 5 = 15 kΩ

Error = \(\frac{16-15}{15}\) × 100 = \(\frac{1}{15}\) × 100 = 6.67%.