Question 351: Current Electricity

Question

Two sources of equal $$emf$$ are connected to an external resistance  $$R.$$ The internal resistance of the two sources are $${R_1}$$ and  $${R_2}\left( {{R_1} > {R_1}} \right).$$ If the potential difference across the source having internal resistance $${R_2}$$ is zero, then

Accepted Answer

$${m I} = {{2\varepsilon } \over {R + {R_1} + {R_2}}}$$
Potential difference across second cell
$$ = V = \varepsilon  - {m I}{R_2} = 0$$
$$\varepsilon  - {{2\varepsilon } \over {R + {R_1} + {R_2}}}.{R_2} = 0$$
$$R + {R_1} + {R_2} - 2{R_2} = 0$$
$$R + {R_1} - {R_2} = 0$$
$$	herefore$$ $$R = {R_2} - {R_1}$$

Answer

$$R = {R_2} - {R_1}$$

Answer

$$R = {R_2} 	imes \left( {{R_1} + {R_2}} ight)/\left( {{R_2} - {R_1}} ight)$$

Answer

$$R = {R_1}{R_2}/\left( {{R_2} - {R_1}} \right)$$

Answer

$$R = {R_1}{R_2}/\left( {{R_1} - {R_2}} \right)$$

Current Electricity

Two sources of equal $emf are connected to an external resistance R. The internal resistance of the two sources are {R_1} and {R_2}\left( {{R_1} > {R_1}} \right). If the potential difference across the source having internal resistance {R_2}$ is zero, then

Choose the correct answer: