Question

In the circuit given below, the resistance between terminals A and B is 7Ω, between terminals B and C is 12Ω and between terminals C and A is 10Ω. The remaining one terminal in each case is assumed to be open. Then the value of RA and RB are _________

(a) RA = 9 Ω and RB = 7 Ω

(b) RA = 2.5 Ω and RB = 4.5 Ω

(c) RA = 3 Ω and RB = 3 Ω

(d) RA = 5 Ω and RB = 1 Ω

Answer 1

The correct option is (b) RA = 2.5 Ω and RB = 4.5 Ω

To explain I would say: Given RA + RB = 7 with C open

RB + RC = 12 with A as open

RA + RC = 10 with B open

Then, RA + RB + RC = \(\frac{29}{2}\) = 14.5

Hence, RA = 2.5 Ω, RB = 4.5 Ω and RC = 7.5 Ω.