How is light used in television?
Like how do we see it?
And what is torque?

Well, that completely depends on the type of television.

Have a read of cathode ray tube (http://en.wikipedia.org/wiki/Cathode-ray_tube), LCD (http://en.wikipedia.org/wiki/LCD), Plasma display (http://en.wikipedia.org/wiki/Plasma_display), LED (http://en.wikipedia.org/wiki/Light-emitting_diode#List_of_LED_applications), and Video projector (http://en.wikipedia.org/wiki/Video_projector).

I'm not sure what you mean by how do we see it... you might want to read up on the eye (http://en.wikipedia.org/wiki/Eye).

Torque is the angular parallel of force. Read torque (http://en.wikipedia.org/wiki/Torque).

Hope those links help.