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 got this question in exam.

Question is taken from Advanced Problems on Two Port Network in portion Two-Port Networks of Network Theory

Answer 1

Correct choice is (c) 111 ± 5.55 Ω

For explanation I would say: R1 = 36 ± 5% = 36 ± 1.8 Ω

R2 = 75 ± 5% = 75 ± 3.75 Ω

∴ R1 + R2 = 111 ± 5.55 Ω.