Question

Electromagnetic waves are traveling straight down towards the center of the earth. For these waves...

A) visible light has a shorter wavelength than infrared light

B) if the electric field points north, the associated magnetic field points east

C) a high-frequency wave has a longer wavelength than a low-frequency wave

D) if the electric field points east, the associated magnetic field points north

E) green light has a higher frequency than violet light

Answer 1

Option a,b,d are correct

Reason for the answer

    a. Visible light wavelengh is about 390 nm to 750 nm. Infrared is about 750 nm to 1mm.

   b. In polarised electromagnetic waves the electric and magnetic fields are always in phase and in planes at 90^o to

      each other.

d. Electric and magnetic fields are mutually perpendicular to each other.

Option c and e are incorrect

c. Due to the frequency wavelength relation,if the wavelength is higher frequency should be lower.

e. Green light frequency is about 668 Hz to 789 Hz, whereas violet is about 526 Hz to 606 Hz.

    wavelength for violet is - 380 nm to 450 nm and green is 495 nm to 570 nm. ( Reason for option c is applicable).