Two cells A and B each of end 20V, are connected in series to an exter...
Given:
- Two cells A and B each of end 20V
- Connected in series to an external resistance R=10ohm
- Internal resistance of cell A is 2 ohm
- Internal resistance of cell B is 3 ohm
To find:
Potential difference between the terminal of cell B
Solution:
When two cells are connected in series, their voltages add up. Therefore, the total voltage across the external resistance R is:
V = V
A + V
Bwhere VA and VB are the voltages of cells A and B respectively. We know that:
V
A = 20V - I
1R
1where I1 is the current flowing through cell A and R1 is the internal resistance of cell A. Similarly,
V
B = 20V - I
2R
2where I2 is the current flowing through cell B and R2 is the internal resistance of cell B. Since the cells are connected in series, the current flowing through both cells is the same:
I
1 = I
2 = I
Therefore,
V = (20V - IR
1) + (20V - IR
2) = 40V - I(R
1 + R
2)
Since the external resistance is R = 10ohm, the current I can be calculated as:
I = V/R = (40V)/(10ohm) = 4A
Substituting the values of R1, R2, and I, we get:
V = 40V - (4A)(2ohm + 3ohm) = 40V - 20V = 20V
Therefore, the potential difference between the terminal of cell B is:
V
B = 20V - I
2R
2 = 20V - (4A)(3ohm) = 8V
Answer:
The potential difference between the terminal of cell B is 8V.