Find `V_(P)-V_(Q)` in the circuit shown in figure.

Options

A. 6.68 V
B. 8 V
C. 4.65 V
D. 7 V

Answer

C

Explanation

In the given circuit, net resistance between P and Q points is `R_(PQ)` and net resistance between Q and R points is `R_(QR)`, then
`R_(PQ) = (10 xx 8)/(10+8) = 80/18 = 40/9 Omega`
`R_(QR) = (10 xx 18xx25)/(10 xx 18xx18xx25+25xx10) = 4500/80=225/44 Omega`
So, circuit will be

In the series circuit, voltages will be divide in the rartio of their resistances.
`therefore R_(PQ)/R_(QR) = V_(PQ)/V_(QR)`
`(40/9)/(225/44)=V_(PQ)/V_(QR)` or `1760/2025 = V_(PQ)/V_(QR)`
or `(1760/3785) = V_(PQ)/10 rArr V_(PQ)=4.65` V