Under what conditions current passing through the resistance R can be increased by short circuiting the battery of emf `E_(2)`. The internal resistances of the two batteries are `r_(1)` and `r_(2)` respectively

Options

A. `E_2r_1 gt E_1(R + r)`
B. `E_1 r_2 gt E_2(R +r_1)`
C. `E_2r_2 gt E_1(R +r)`
D. `E_1r_1gtE_2(R +r_1)`

Answer

B

Explanation

Currrent through R before short- circuiting second cell
`I = (epsilon_(1) +epsilon_(2))/(R +(r_(1)+r_(2)))`
Current through R after short- circuiting second cell
`I' = (epsilon_(1))/( R+ r_(1))`
Here, `I' gt I or epsilon_(1)r_(2) gt epsilon_(2)(R +r_(1))`