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Question : 8
Total: 8
(a) Write the expression for the force
m q
(b) Show that the kinetic energy of the particle moving in magnetic field remains constant.
(b) Show that the kinetic energy of the particle moving in magnetic field remains constant.
Solution:
(a) Expression for force acting on charged particle 1
(i) Condition for circular path
(ii) Condition for helical path
(b) Showing Kinetic energy is constant
(a)
= q (
× B )
(i) When velocity of charged particle and magnetic field are perpendicular to each other.
(ii) When velocity is neither parallel nor perpendicular to the magnetic field.
(b) The force, experienced by the charged particle, is perpendicular to the instantaneous velocity, at all instants. Hence the magnetic force cannot bring any change in the speed of the charged particle. Since speed remains constant, the kinetic energy also stays constant.
(i) Condition for circular path
(ii) Condition for helical path
(b) Showing Kinetic energy is constant
(a)
(i) When velocity of charged particle and magnetic field are perpendicular to each other.
(ii) When velocity is neither parallel nor perpendicular to the magnetic field.
(b) The force, experienced by the charged particle, is perpendicular to the instantaneous velocity, at all instants. Hence the magnetic force cannot bring any change in the speed of the charged particle. Since speed remains constant, the kinetic energy also stays constant.
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