What value of series resistor is needed for full scale deflection on a 50 microamp DC meter with an applied voltage of 200 volts DC?

To determine the value of the series resistor needed for full-scale deflection on a 50 microamp DC meter with an applied voltage of 200 volts DC, it's important to consider how a meter operates within a circuit.

When properly set up, the meter registers current passing through it, and the full-scale deflection indicates the maximum current it can measure, which in this case is 50 microamps (0.00005 amperes). Given the applied voltage is 200 volts, we can use Ohm's law (V = I * R) to find the series resistance.

The total current flowing through the circuit at full scale is 50 microamps. The voltage across the series resistor can be calculated by subtracting the meter's voltage drop from the applied voltage. However, in this case, we need to find the total resistance required to allow 50 microamps to flow when 200 volts is applied.

Using Ohm's law, we solve for R:

R = V / I = 200 volts / 0.00005 amperes = 4,000,000 ohms or 4 megohms.

This calculation shows that the series resistor must be 4 megohms to ensure that the meter receives the