CET Answers

 Tinted lenses

 optician provides the answers to CET module C1183 (April 8)

 1 Which of the following is not part of the electromagnetic spectrum?
(A) Radio; (B) Microwave; (C) Sound; (D) X-rays.
The correct answer is C. Sound is a compression wave requiring a medium through which to travel and not an electromagnetic radiation.

2 Which of the following has the shortest wavelength? (A) Infra-red;
(B) UVA; (C) UVB; (D) UVC.
The correct answer is D. The wavelength of UVC is 100 to 280nm, shorter than the other radiations.

3 Which of the following is absorbed by the ozone layer? (A) Infra-red; (B) UVA; (C) UVB; (D) UVC.
The correct answer is D. UVC is absorbed by the ozone layer and therefore does not have any effect on the human eye.