AP EAMCET202017 Sep 2020Morning ShiftPhysicsCurrent ElectricityActual
In a potentiometer experiment the balancing length with a cell is (560 ~cm ). When an external resistance of (10 ) is connected in parallel to the cell, then the balancing length changes by (60 ~cm ). Find the internal resistance of the cell.
Options
- A(1 )
- B(2 )
- C(1.2 )
- D(2.1 )
Correct answer
C. (1.2 )
Step-by-step solution
Given, (l₁=560 ~cm , R=10 ), ( aligned & l₂=l₁-60 & l₂=560-60=500 ~cm aligned ) ( ) Internal resistance of cell is given by ( aligned & r= ( l₁-l₂ l₂ ) R= ( 560-500 500 ) 10 & = 60 500 10= 6 5 =1.2 aligned )