Question

A voltmeter of resistance 998 \(\Omega\) is connected across a cell of emf 2 V and internal resistance 2\(\Omega\). The potential difference across the voltmeter is

• A. 1.99 V
• B. 3.5 V
• C. 5 V
• D. 6 V

Hint:

A voltmeter with high resistance causes minimal current draw, so terminal voltage \(\approx\) emf. The small drop is across internal resistance.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Current in circuit \(I = \dfrac{E}{R_{voltmeter} + r}\). Voltmeter reading \(= IR_{voltmeter}\).
Step 2: Detailed Explanation:
\[ I = \frac{2}{998 + 2} = \frac{2}{1000} = 2 \times 10^{-3} \text{ A} \] \[ V = I \times 998 = 2 \times 10^{-3} \times 998 = 1.996 \approx 1.99 \text{ V} \]
Step 3: Final Answer:
Potential difference \(= \mathbf{1.99}\) V.