A particle of mass m
and charge q
is fastened to one end of a string of length l
. The other end of the string is fixed to the point O
. The whole system lies on a frictionless horizontal plane. Initially, the mass is at rest at A
. A uniform electric field in the direction shown is then switched on. Then
- the speed of the particle when it reaches B is √2qElm
- the speed of the particle when it reaches B is √qEl2m
- the tension in the string when particles reach at B is qE.
- the tension in the string when the particles reach at B is 2qE.