which of the following is not a characteristic of electromagnetic light waves? a. they can't travel through a vacuum. b. they obey the formula: velocity= wavelength x frequency. c. they can be reflected and refracted. d. they travel at approximately 3 x 108 meters per second through the air.

The magnitude of the magnetic field at a certain distance from a long, straight conductor is represented by b. what is the magnitude of the magnetic field at twice the distance from the conductor? a. at twice the distance, the magnitude of the field is 4b.b. at twice the distance, the magnitude of the field is 2b.c. at twice the distance, the magnitude of the field is b/2.d. at twice the distance, the magnitude of the field is b/4.e. at twice the distance, the magnitude of the field remains equal to b.