Neet Solved Paper 2015 Question 29

Question: A, B and C are voltmeters of resistance R, 1.5R and 3R respectively as shown in the figure. When some potential difference is applied between X and Y, the voltmeter readings are $ V _{A},V _{B} $ and $ V _{C} $ respectively. Then,

Options:

A) $ V _{A}=V _{B}=V _{C} $

B) $ V _{A}\ne V _{B}=V _{C} $

C) $ V _{A}=V _{B}\ne V _{C} $

D) $ V _{A}\ne V _{B}\ne V _{C} $

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Answer:

Correct Answer: A

Solution:

The equivalent resistance between Q and S is given by

$ \frac{1}{R’}=\frac{1}{1.5R}+\frac{1}{3R}=\frac{2+1}{3R} $

$ \Rightarrow ,R’=R $ Now, $ V _{PQ}=V _{A}+IR $ Also

$ V _{QS}=V _{B}=V _{C}=IR $ Hence, $ V _{A}=V _{B}=V _{C} $