Acoil of wire with a current is called a(n)

Which is not a source of noise pollution? a)airplanes b)acid rain c)machines d)cars

Iwill give brainliest if you answer right : )

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?