Question

Voltmeters `V_(1)` and `V_(2)` are connected in series across a `D.C.` line `V_(1)` reads 80 volts and has a per volt resistance of `200 ohms`, `V_(2)` has a total resistance of 32 kilo ohms.
The line voltage is

Answer 1

Correct Answer - `240V`
The resistance `R_(1)` of voltage `V_(1)` is given by `R_(1) = 80 xx 200 = 16000 Omega = 16 k Omega`
Current in the circuit
`I = (V_(1))/(R_(1)) = (80)/(16000) = 5 xx 10^(-3)A`
Reading of second voltmeter
`V_(1) = IR_(2) = (5 xx 10^(-3)) xx (32 xx 10^(3)) = 160 V`
`:.` Let voltage `V= V_(1) + V_(2) = 80 + 160 = 240 V`