Question

If the reading of the ideal ammeter shown in the figure below is 3A, then choose the correct statement(s).

• A. The reading of the ideal voltmeter depends on R
• B. The reading of the ideal voltmeter is independent of R
• C. Potential of A is more than potential of B whatever be the value of R

Answer 1

Answer: (A), (C)

The reading of the ideal voltmeter depends on R, Potential of A is more than potential of B whatever be the value of R

Answer 2

Solution Explanation:

1. Analysis of the Circuit:

   • The current reading of 3 A in the top branch (via the ideal ammeter) fixes the current through that branch, but the voltage division across the resistors in that branch depends on $R$. Hence, the potential difference (and thus the voltmeter reading, which is taken in parallel with a voltage source in the bottom branch that is influenced by the circuit’s overall potential constraints) ultimately depends on $R$.

   • Examining the circuit potentials using Kirchhoff’s laws shows that point A is at a higher potential than point B regardless of the value of $R$.

2. Conclusion:

   • Statement 1: "The reading of the ideal voltmeter depends on $R$" is correct.
   • Statement 2: "The reading of the ideal voltmeter is independent of $R$" is incorrect.
   • Statement 3: "Potential of A is more than potential of B whatever be the value of $R$" is correct.