JEE Main 2020 — Current Electricity Question with Solution
From: JEE Main 2020 (Online) 7th January Evening Slot
Question
The balancing length for a cell is 560 cm in a potentiometer experiment. When an external
resistance of 10 is connected in parallel to the cell, the balancing length changes by 60 cm. If
the internal resistance of the ceil is
, where N is an integer then value of N is .............
Enter your answer
Show full solutionCorrect answer: 12
Correct answer
12
Step-by-step explanation
Let the emf of cell is internal resistance is 'r' and potential gradient is x.
When only cell connected :
= 560x .....(1)
After connecting the resistor
= 500x ....(2)
from (1) and (2)
56 = 50 +5r
r = =
N = 12
When only cell connected :
= 560x .....(1)
After connecting the resistor
= 500x ....(2)
from (1) and (2)
56 = 50 +5r
r = =
N = 12
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