JEE Main20202 Sep 2020Evening ShiftPhysicsCurrent ElectricityActual
A potentiometer wire PQ of 1 m length is connected to a standard cell E 1 . Another cell E 2 of emf 1 . 02 V is connected with a resistance ' r ' and switch S (as shown in figure). With switch S open, the null position is obtained at a distance of 49 cm from Q . The potential gradient in the potentiometer wire is :
Options
- A0 . 02   V / cm
- B0 . 01   V / cm
- C0 . 03   V / cm
- D0 . 04   V / cm
Correct answer
A. 0 . 02   V / cm
Step-by-step solution
P Q = 1   m Q J = 49   cm ∴   P J = 51   cm v ℓ = 1 . 02 51 = 0 . 02   v / cm