Electrical Math

What value of series resistor would be needed to obtain a full scale deflection on a 50 microamp DC meter with an applied voltage of 200 volts DC?

Answer

4 megohms.

R = V / I = 200 V / 50 uA = 4,000,000 ohms = 4 megohms.

Source: FCC Element 3 question pool, 3B

Not the answer

  • 400 kilohms.
  • 200 kilohms.
  • 2 megohms.

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