Three cells each of e.m.f 1.5 V and internal resistance 2.5Ω are connected as shown in the diagram above. Find the net e.m.f and the internal resistance
- 1.5V, 7.50Ω
-
1,5V, 0.83Ω
- 4.5V, 7.50Ω
- 4.5V, 0.83Ω
The correct answer is: B
Explanation
Since the cells are connected in parallel the net e.m.f is that of one cell, E.However the effective internal resistance should be added as parallel resistance.
=> 1/v + 1/25 + 1/25 + 1/25 = 1.2
∴ v = 0.83Ω
∴ Effective e.m.f and internal resistance are respectively = 1.5V and 0.83Ω