A straight conductor of area of cross-section S and resistivity `rho` is connected to a ballistic galvometer. The conductor is moved with speed v and stoped suddenly. The ballistic gal=vom=nometer registors flow of q couloumbs of electricity Show that this observation can be used to measure `(e)/(m)` of electrons.
"["Hint: Orderly motion of elcctrons is throuwn into randon motion within relaxation time `tau`"]"
