A 50 microampere meter movement has an internal resistance of 2,000 ohms. What applied voltage is required to indicate half-scale deflection?

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Multiple Choice

A 50 microampere meter movement has an internal resistance of 2,000 ohms. What applied voltage is required to indicate half-scale deflection?

The meter’s deflection is proportional to the current through its coil. Half-scale means half of the full-scale current, so the required current is 25 microamps (half of 50 μA). With an internal resistance of 2000 ohms, the voltage needed across the meter is V = I × R = 25 μA × 2000 Ω = 0.05 V. Therefore, the applied voltage for half-scale is 0.05 volts. For context, full-scale would require 0.10 V, and the other voltage values would produce currents that do not reach half-scale.

The meter’s deflection is proportional to the current through its coil. Half-scale means half of the full-scale current, so the required current is 25 microamps (half of 50 μA). With an internal resistance of 2000 ohms, the voltage needed across the meter is V = I × R = 25 μA × 2000 Ω = 0.05 V. Therefore, the applied voltage for half-scale is 0.05 volts. For context, full-scale would require 0.10 V, and the other voltage values would produce currents that do not reach half-scale.

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