JEE Main 2022 — Current Electricity Question with Solution
From: JEE Main 2022 (Online) 24th June Morning Shift
Question
In a potentiometer arrangement, a cell gives a balancing point at 75 cm length of wire. This cell is now replaced by another cell of unknown emf. If the ratio of the emf's of two cells respectively is 3 : 2, the difference in the balancing length of the potentiometer wire in above two cases will be ___________ cm.
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Show full solutionCorrect answer: 25
Step-by-step explanation
At balancing point, we know that emf is proportional to the balancing length. i.e.,
emf balancing length
Now, let the emf's be 3 and 2.
3 = k(75) ..... (1)
and 2 = k(l) ....... (2)
l = 50 cm
Difference is (75 50) cm = 25 cm.
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