AP EAMCET20227 Jul 2022Evening ShiftPhysicsCurrent ElectricityActual
Two cells A and B are connected in the secondary circuit of a potentiometer one at a time and the balancing lengths are respectively 360 ~cm and 420 ~cm . If emf of A is 2.4 ~V , the emf of the second cell B is
Options
- A2.8 ~V
- B3.2 ~V
- C3.0 ~V
- D2.6 ~V
Correct answer
A. 2.8 ~V
Step-by-step solution
If E₁ and E₂ are emf's of cells with l₁ and l₂ balance lengths in a potentiometer experiment, then, E₁ E₂ = l₁ l₂ or E₂=E₁ l₂ l₁ Here, E₁=24 ~V , l₁=360 ~cm and l₂=420 ~cm Substituting values in Eq. (i), we get E₂=24 420 360 =28 ~V So, emf of cell B is 2.8 ~V .