Voltmeter Accuracy – Rankers Physics

Measuring Devices ( Galvanometer, Voltmeter and Ammeter & Meter Bridge ): Practice Problem & Solution

Assertion (A): A voltmeter is an inherently inaccurate instrument. Reason (R): A voltmeter is always connected in parallel in a circuit.  
(1) Both (A) & (R) are true and the (R) is the correct explanation of the (A)
(2) Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(3) (A) is true but (R) is false
(4) Both (A) and (R) are false

Solution Explained:

To solve this problem, we apply the core principles of Measuring Devices ( Galvanometer, Voltmeter and Ammeter & Meter Bridge ). Understanding the underlying formula is key to arriving at the correct answer below:

Assertion (A) is true, as any real voltmeter has finite resistance and draws some current, perturbing the circuit. Reason (R) is true; voltmeters are always connected in parallel. However, (R) is not the correct explanation for (A).

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