JEE Main 2019 — Current Electricity Question with Solution
From: JEE Main 2019 (Online) 8th April Evening Slot
Question
In the circuit shown, a four-wire potentiometer
is made of a 400 cm long wire, which extends
between A and B. The resistance per unit length
of the potentiometer wire is r = 0.01 /cm. If
an ideal voltmeter is connected as shown with
jockey J at 50 cm from end A, the expected
reading of the voltmeter will be :-
This question includes a diagram. The text above accompanies the figure.
Choose an option
Show full solutionCorrect option: A
Correct answer
A0.25 V
Step-by-step explanation
Resistance of wire AB = 400 × 0.01 = 4
i =
Now voltmeter reading = i (Resistance of 50 cm length)
= (0.5 A) (0.01 × 50) = 0.25 volt
i =
Now voltmeter reading = i (Resistance of 50 cm length)
= (0.5 A) (0.01 × 50) = 0.25 volt
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