Question
Physics Question on Current electricity
A cell of emf 1.1 V and internal resistance 0.5 Ω is connected to a wire of resistance 0.5 Ω. Another cell of the same emf is now connected in series with the intention of increasing the current but the current in the wire remains the same. The internal resistance of the second cell is________.
Fill in the blank with the correct answer from the options given below.
A
1 Ω
B
2.5 Ω
C
1.5 Ω
D
2 Ω
Answer
1.5 Ω
Explanation
Solution
The internal resistance must balance the added emf. Using Kirchhoff’s law, the internal resistance of the second cell is calculated to be 1.5 Ω.