Question

A charged particle having initial velocity v enters into a region of uniform magnetic field perpendicular to v where it is subjected to a magnetic force. The kinetic energy of a particle - 

1 point

remains unchanged

decreases

increases

is reduced to ​

Answer 1

The kinetic energy of a particle decreases

Answer 2

Answer:

ok so

force on a charge in magnetic field is q V × B

now as force is perpendicular to velocity always and hence

hence it is perpendicular to displacement

which means it does not do any work

which means its work done is zero

hence energy of particle does not change

hence remains unchanged.