Voltmeter Loading Effect

Question

Resistors $$R_1$$ and $$R_2$$ are connected in series. A voltmeter with internal resistance $$R_v$$ is used to measure the potential difference across $$R_2$$. Which of the following represents the ratio of the measured voltage, $$V_{measured}$$, to the actual voltage across $$R_2$$ without the voltmeter, $$V_{actual}$$?

Accepted Answer

$$\frac{V_{measured}}{V_{actual}} = \frac{R_v}{R_2 + R_v} \cdot \frac{R_1 + R_2}{R_1 + \frac{R_2 R_v}{R_2 + R_v}}$$

Answer

$$\frac{V_{measured}}{V_{actual}} = \frac{R_v R_2}{(R_v + R_2) R_2}$$

Answer

$$\frac{V_{measured}}{V_{actual}} = \frac{R_2}{R_2+R_v}$$

Answer

$$\frac{V_{measured}}{V_{actual}} = \frac{R_v}{R_1 + R_v}$$

Voltmeter Loading Effect

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