Initially unpolarized light is sent into a system of three polarizing sheets whose polarizing directions make angles of θ1 = 40°, θ2 = 20°, and θ3 = 40° with the direction of the y axis. What percentage of the light's initial intensity is transmitted by the system?

Modern physics a photon emitted from an excited hydrogen atom has an energy of 3.02 electron volts. which electron energy-level transition would produce this photon? a. n=1 to n=6 b. n=2 to n=6 c. n=6 to n=1 d. n=6 to n=2 i chose b but the correct answer is d can someone tell me why? and what's the difference?