A cell of emf 12 V and internal resistance `6Omega` is connected in parallel with another cell of emf 6 V ad internal resistance `3Omega`, such that the positive of the first cell joins the positive to the second cell and similarly the negative of first cell joins the negative of the second cell. A bulb of filament resistance `14Omega` is connected across the combination. The power delivered to be bulb is

Options

A. 4.0 W
B. 3.5 W
C. 8.5 W
D. 2.5 W

Answer

B

Explanation

`i=(E_(eff))/(R_(eff)),p=i^(2)R`