Question

Please help!

36. Which of the following is a true statement?
a. frequency is the number of oscillations of a wave per unit of time
b. intensity is the number of photons per unit of area or volume
c. frequency determines the energy of a light wave, while intensity determines its brightness
d. all these choices are correct


39. The wavelength of an electromagnetic wave
a. is equal to its frequency divided by the speed of light
b. is equal to the speed of light divided by its frequency
c. is equal to its frequency multiplied by Planck's constant
d. is equal to its energy divided b