Two batteries, one of emf 18 volts and internal resistance `2 Omega` and the other fo emf 12 volts and internal resistance `1 Omega`, are connected as shown. The voltmeter `V` will record a reading of

Options

A. 18V
B. 16V
C. 14 V
D. 12 V

Answer

C

Explanation

The two cell oppose each other.
`therefore` The effective e.m.f. in the closed circuit =18-12=6 V and the net resistance in the circuit `=1+2=3 Omega`
`therefore I=(6)/(3)=2 A`
`therefore` P.D. across V=Terminal voltage of `E_(1) or E_(2)`
`therefore` For `E_(1)` terminal `P.D.=E_(1)-Ir_(1)=18-(2xx2)=14 V`
`therefore` The voltmeter reading will be 14 V.