A point charge is placed in a moving train. A passenger A sitting in the train and person B on the ground observe the fields due to this charge. Then

Step-by-step solution

For observer A sitting in the train, the point charge is at rest. A stationary charge produces only an electric field. Thus, A observes only an electric field. For observer B standing on the ground, the point charge is moving with the velocity of the train. A moving charge produces both an electric field and a magnetic field. Thus, B observes both electric and magnetic fields. Answer: B observes both electric and magnetic fields