Question

Given that, R1 = 36 Ω and R2 = 75 Ω, each having tolerance of ±5% are connected in series. The value of resultant resistance is ___________

(a) 111 ± 0 Ω

(b) 111 ± 2.77 Ω

(c) 111 ± 5.55 Ω

(d) 111 ± 7.23 Ω

I had been asked this question in examination.

The doubt is from Advanced Problems on Network Theorems topic in section Useful Theorems in Circuit Analysis of Network Theory

Answer 1

Right choice is (c) 111 ± 5.55 Ω

Best explanation: R1 = 36 ± 5% = 36 ± 1.8 Ω

R2 = 75 ± 5% = 75 ± 3.75 Ω

∴ R1 + R2 = 111 ± 5.55 Ω.