A long cylindrical wire carries a positive charge of linear density `2.0 xxx 10^(-8) C m^(-1). An electron revolves around it in a circular path under the influence of the attactive 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.`