Sourup Nag The circuit can be simplified as above. It makes a wheat stone bridge. So no current flows through 8 ohm resistor.
Equivalent resistance of the upper part = (7+35) ohm = 42 ohm. So current in upper part = 1 ampere. So power in 5 ohm resistance = 1 ampere * 5 volt = 5 watt (5 volt is the potential across 5 ohm resistor)
Since no current flows through 8 ohm resistor, so power in 8 ohm resistor is 0.