an electric cell with nominal voltage E has a resistance of 3Ω connected across it. If the voltage falls to 0.6E, the internal resistance of the cell is
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Correct Answer: Option C
Explanation:
I = V/R = 0.6E/3 = 0.2E
Again, I = E / (R+Ï’) = E / (3+Ï’)
Divide eqn (2) by eqn (1)
I/I = E / (3+Ï’) x I / 0.2E
=> 0.2(3+Ï’) = 1
0.6 x 0.2Ï’ = 1
∴0.2ϒ = -0.6
=> ϒ = 0.6 / 0.2 = 3Ω
ϒ = 3Ω
I = V/R = 0.6E/3 = 0.2E
Again, I = E / (R+Ï’) = E / (3+Ï’)
Divide eqn (2) by eqn (1)
I/I = E / (3+Ï’) x I / 0.2E
=> 0.2(3+Ï’) = 1
0.6 x 0.2Ï’ = 1
∴0.2ϒ = -0.6
=> ϒ = 0.6 / 0.2 = 3Ω
ϒ = 3Ω