17 (a) an infinitely long positively charged straight wire has a linear charge density of lamda cm(inverse). and electron is revolving around the wire as its centre with a constant velocity in a circular plane perpendicular to the wire. deduce the expression for its kinetic energy.
(b) plot a graph of the kinetic energy as a function of charge density lamda.
ELECTRIC FIELD due to the infinitely long positively charged wire,
E=λ/2π ε0 r
also the centripetal force required by the electron to revolve is given by
the electrostatic force of attraction between the electron and wire
F2=eλ/2π ε0 r (2)
equate 1 and 2 and try to get an expression for kinetic energy in terms of (mv^2)/2
the plot should be a straight line as both the quantities are directly proportional to each other