A particle of mass m and charge q is released from rest in a uniform electric field. If there is no other force on the particle, the dependence of its speed v on the distance x travelled by it is correctly given by (graphs are schematic and not drawn to scale)

Step-by-step solution

The particle is at rest initially. So, the initial velocity u = 0 m s - 1 . The force on the charged particle in the uniform electric field, F = q E ⇒ m a = q E ⇒ a = q E m Applying the velocity-displacement equation under constant acceleration, v 2 = u 2 + 2 a x ⇒ v 2 = 0 2 + 2 q E m x ⇒ v 2 = 2 q E m x