Question

Infrared radiations are produced when a changing electric field creates a...

longitudinal wave perpendicular to it
changing magnetic field parallel to it
changing magnetic field perpendicular to it
longitudinal wave parallel to it

Answer 1

changing B field perpendicular. Light is electromagnetic waves, which means that E and B are both perpendicular to each other. To get the propagating direction, it's the right hand rule of ExB. Hope this helps :)