Q

# kindly solve

10 identical cell in series are connected to the ends of a resistance of 59$\Omega$,the current is  found to be 0.25A. But when the same cells being connected in parallel,are joined to the ends of a resistance of 0.05$\Omega$,the current is 25A EMF of  each cell is

A.

1V

B.

0.5V

C.

1.5V

D.

2V

Views

In series: $I=\frac{E_{eq}}{R+r_{eq}}$

$E_{eq}=10E \: \: and\: \: r_{eq}=10r,I=0.25A$

$\therefore 0.25=\frac{10E}{59+10r}\: \: or\: \: 10E=2.5r+14.75.....(1)$

In parallel: $E_{eq}=E \: \: and\: \: r_{eq}=r/10,I=25A$

$\therefore 25=\frac{E}{0.05+\frac{r}{10}}\: \: or\: \: E=1.25+2.5r.....(2)$

(1)-(2)

$13.5=9E\: \: or\: \: E=1.5V$

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