Question 673: Current Electricity

Question

The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 $$\Omega $$ is

Accepted Answer

$$I = {\varepsilon  \over {R + r}}$$
$$ \Rightarrow IR + Ir = \varepsilon $$
Here,
$$R = 10\Omega ,r = ?,\varepsilon  = 2.1V,I = 0.2A$$
$$ 	herefore $$ 0.2 ÃÂ 10 + 0.2 ÃÂ r = 2.1
2 + 0.2r = 2.1
0.2r = 0.1 $$ \Rightarrow $$ r = $${1 \over 2}$$ = 0.5 $$\Omega $$

Answer

0.8 $$\Omega $$

Answer

1.0 $$\Omega $$

Answer

0.2 $$\Omega $$

Answer

0.5 $$\Omega $$

Current Electricity

The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 $\Omega $ is

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