A long cylindrical wire carries a positive charge of linear density `2.0 x 10^(-8) C m^(-1). An electron revolves around it in a circular path under the influence of the attractive electrostatic force. Find the kinetic energy of the electron. Note that it is independent of the radius.

Explanation

Solution to the previous question
`E = lambda/ 2 pi r epsilon_0 r `
` E xx q = mv^2/r (centripetal force)`
` or (lambda/ 2 pi r epsilon_0 r ) xx q = mv^2/r`
` or Kinetic energy 1/2 mv^2 `
` = (lambda/2pi (epsilon_0))`
` = 9 xx (10^9) xx 2 xx (10^-8) xx 1.6 xx (10^-19)`
`= 2.88 xx (10^-17)J.`