Question

Please tell the answer and procedure.

Answer 1

Assume that the current is flowing from right to left. That is, current is flowing across BD and from 30V to 15V. Take the potential at B as x and D as 0. Then we get the following equation using Kirchoff's first law or junction law:

x-30/3= 15-x/6 + 0-x/3

We get x=15

Therefore current flowing through BD would be 15/3=5

Also, if you have a doubt in the equation...

Current flowing from 30 V battery through 3 ohm resistor is x-30/3.

Here the current splits.

Current through BD would be 0-x/3 (D is at higher potential)

and through 6 ohm resistor would be 15-x/6.

Hope, you understood.

If you have any doubts, please ask.