Two batteries with emf 12 V and 13V are connected in parallel across a load resistor of `10Omega` . The internal resistances of the two batteries are `1Omega and 2Omega` respectively . The voltage across the load lies between

Options

A. 11. 6 V and 11.7 V
B. 11.5 V and 11.6 V
C. 11.4 V and 11.5 V
D. 11.7 V and 11.8 V

Answer

B

Explanation

Using Kirchhoff.s law at P we get
`(V - 12)/( 1 ) + ( V- 13)/( 2) + (V-0)/( 10) = 0 `
Let potential at P, Q, U = 0 and at R=V
`rArr (V )/ (1) + ( V)/(2) + (V )/( 10) = (12)/( 1) + (13) /(2) + (0) /( 10)`
`rArr ( 10 + 5 + 1)/( 10 ) V = ( 24+ 13)/( 2) rArr V ((16)/(10)) = ( 37)/( 2)`
`rArr V = ( 37 xx 10)/( 16 xx 2) = ( 370)/( 32) = 11.56` volt