2018 - JAMB Physics Past Questions and Answers - page 9

The primary reason that power is transmitted at high voltages is to increase efficiency. As electricity is transmitted over long distances, there are inherent energy losses along the way. High voltage transmission minimizes the amount of power lost as electricity flows from one location to the next. ~ Betaengineering.com

F = 20cm

  V = 100cm

  U = ?

  \(\frac{1}{U}\) + \(\frac{1}{V}\) = \(\frac{1}{F}\)

\(\frac{1}{20}\) + \(\frac{1}{100}\) = \(\frac{1}{F}\)

  5 + \(\frac{1}{100}\) = \(\frac{1}{F}\)

  F = \(\frac{100}{6}\)

  = 16.7cm

  = 17cm