JEE Main202122 Jul 2021Morning ShiftPhysicsCurrent ElectricityActual
In an electric circuit, a call of certain emf provides a potential difference of 1 . 25 V across a load resistance of 5 Ω . However, it provides a potential difference of 1 V across a load resistance of 2 Ω . The emf of the cell is given by x 10 V . Then the value of x is .
Correct answer
0
Step-by-step solution
Terminal voltage, v = i R = E R R + r 1 s t → 1 . 25 = E ( 5 ) 5 + r     … i 2 nd → 1 = E ( 2 ) 2 + r     … ii By i  and   ii , r = 1   Ω ,   E = 3 2   V = 15 10   volt ⇒ x = 15