Last Week's Question

A truck on a highway

A large truck with an absolute capacitance of 1,100 pF accumulates 3 μC of charge as it travels down the road. What is the approximate voltage of the truck relative to the earth?

  1. 38 kV
  2. 13 kV
  3. 2.7 kV
  4. 1.5 kV


The correct answer is "c". The charge on an object divided by its absolute capacitance is its voltage relative to a distant uncharged ground.

Cars and trucks can accumulate charge generated by the tires as they roll over non-conductive surfaces. Charge can also be generated during the transfer of passengers or payloads.

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