Two identical cells each of emf 2V and internal resistance 1.0W are connected in parallel. The combination is connected to an external load of 1.5W. Calculate the current in the circuit.

1.5 ampere

Explanation:

Given that

Power P = 1.5 W

For each:

EMF = 2v

Internal resistance = 1 ohms

Total EMF since in parallel is

EMF = 1/E1 + 1/E2= 1/Et

I/Et = 1/2 + 1/2 = 1/1

Et = 1/1 = 1 V total

For total resistance:

1/Rt = 1/R1 + 1/R2

1/Rt = 1/1 + 1/1 = 1/1

Rt = 1 ohms total

Power = IV

where I is the current,

V is the voltage

1.5 = I x 1

I = 1.5/1 = 1.5 amp

vapour or gas assuming atmospheriv pressure