Question

An accumulator battery (storage cell) B of emf E and internal resistance r is being charged from a DC supply whose terminals are $T_1$ and $T_2$ :

• A. potential difference between $T_1$ and $T_2$ must be > E
• B. $T_1$ must be positive with respect to $T_2$
• C. in the battery, current flows from the positive to the negative terminal
• D. all the above options are incorrect

Answer 1

Answer: (A), (B), (C)

The correct options are
A potential difference between $T_1$ and $T_2$ must be > E
B $T_1$ must be positive with respect to $T_2$
C in the battery, current flows from the positive to the negative terminal

1) The first option is correct as the dc potential is charging the cell its potential should be greater than the battery potential otherwise battery would have been charging the potential which is contradictory.
2) Since for charging the battery the potential across battery should be ,
$V=E+Ir$,

so the current should flow from positive to negative terminal of battery.
3) For current to flow from negative to positive terminal of battery the $T_1$ should be positive with respect to $T_2$ as $E<$ the potential between $T_1$ and $T_2$.