A place of electro-magnetic wave of frequency 25 MHz travell in a free space along x-direction. At a particular point in space and time, `E=6.3 hatJbarB v//m`. What is ` bar B` at that point?

A plane electromagnetic wave of frequency 10MH tranvells in free space along the x-direction. At a particular pointy in space and time. E= 2.7 V//m . What is B at this point?

Two particles, each of mass m and speed v_3 travel in opposite directions along parallel lines separated by a distance d. Show that the vector angular momentum of the two particle system is the same whatever be the point about which the angular momentum is taken.