JEE Main20208 Jan 2020Evening ShiftPhysicsCurrent ElectricityActual
The series combination of two batteries, both of the same emf 10 V , but different internal resistance of 20   Ω and 5   Ω , is connected to the parallel combination of two resistors 30   Ω and x  Ω . The voltage difference across the battery of internal resistance 20   Ω is zero, the value of x (in Ω ) is____
Correct answer
0
Step-by-step solution
V 1 = ϵ 1 - i . r 1 0 = 10 - i × 20 i = 0.5 A V 2 = 7.5 30 + 7.5 x 0.5 = 0.25 + 7.5 x 7.5 x = 0.25 x = 7.5 0.25 = 30   Ω