Two sources of current of equal emf are connected in series and having different internal resistance `r_1` and `r_2(r_2gtr_1)`. Find the external resistance `R` at which the potential difference across the terminals of one of the sources becomes equal to zero.

Two sources of equal emf are connected in series and having different internal resistance r_1 and r_2(r_2gtr_1) . Find the external resistance R at which the potential difference across the terminals of one of the sources becomes equal to zero.

Two cells, whose e.m.f.'s are same are connected in series. Their internal resistance are r_1 and r_2 respectively and r_1gtr_2 . When this combination is connected with an external resistance R then potential difference between the terminals of first cell becomes zero. The value of resistance R will be

If E is the emf of a cell of internal resistance r and external resistance R, then potential difference across R is given as

If E is the emf of a cell of internal resistance r and external resistance R, then potential difference across R is given as

Two cells with the same emf E and different internal resistances r_(1) and r_(2) are connected in series to an external resistances R . The value of R so that the potential difference across the first cell be zero is

Tow cells with the same emf E and different internal resistances r_(1) and r_(2) are connected in series to an external resistances R . The value of R so that the potential difference across the first cell be zero is

Two cells of emf 2E and E with internal resistance r_(1) and r_(2) respectively are connected in series to an external resistor R (see figure). The value of R, at which the potential difference across the terminals of the first cell becomes zero is