shown a network of four resistance and three batteries

Which of the batteries is getting charged.

Options

A. only 6V
B. both 6V and 15V
C. only 15V
D. none

Answer

A

Explanation

Left loop :
`V_F +6 +4I_1 - 30 +2I_1 = V_F`
`I_4 = 4A`

Right loop :
`V_F +6+ 1I_2 - 15 + 2I_2 =V_F 30V`
or `I_2 =3A`
Net current through 6V battery is
`I = I_1 +I_2 = 4+3 = 7A`
The 6 V battery is getting charged. Both 15V and 30V batteries
produce current in 6V battery.