Voltmeters V1 and V2 are connected in series across a D.C. line. V1 reads 80 volts and has a per volt resistance of 200 ohms. V2 has a total resistance of 32 kilo-ohms. The line voltage is

R1 =80 × 200 =16000 Ω =16  kΩCurrent flowing through V1 = Current flowing throughV2  =8016 × 103 =5  ×  10−3 ASo, potential difference across V2 isV2  =5  ×  10−3×32  ×  10−3 = 160  voltHence, line voltage , V = V1 + V2 = 80 + 160 = 240 V