Question 288: Current Electricity

Question

Two cells of same emf but different internal resistances r
1
and r
2
are connected in series with a resistance R. The value of resistance R, for which the potential difference across second cell is zero, is :

Accepted Answer

$$I = {{2\varepsilon } \over {R + {r_1} + {r_2}}}$$
As per the question,
$${{2\varepsilon } \over {R + {r_1} + {r_2}}} 	imes {r_2} - \varepsilon  = 0$$
$$ \Rightarrow R = {r_2} - {r_1}$$

Answer

r
2
$$-$$ r
1

Answer

r
1
$$-$$ r
2

Answer

r
1

Answer

r
2

Current Electricity

Two cells of same emf but different internal resistances r 1 and r 2 are connected in series with a resistance R. The value of resistance R, for which the potential difference across second cell is zero, is :

Choose the correct answer: