The angle of incidence is the angle between the WHAT and the normal of the surface?

What are the applications of electromagnetic waves

Two point charges are separated by a certain distance. how does the strength of the electric field produced by the first charge, at the position of the second charge, change if the second charge is doubled? a. the field does not change b. the field strength decreases by half. c. the field strength doubles d. the field strength quadruples

To a of 4 x hz is 1. 0. mm nm nm