Question

Which of the following electromagnetic waves is used in high precision application like LASIK eye surgery?
A. Microwave
B. Ultraviolet rays
C. Gamma rays
D. X-rays

Answer 1

Hint: As mentioned in the question, we require an electromagnetic wave which can give us high precision. Smaller the wavelength of an electromagnetic radiation, higher is the precision offered by that radiation in applications like LASIK eye surgery.

Complete step by step answer:
We are asked to find out the radiation which can be used in high precision applications.
In high precision applications like LASIK eye surgery, we want to probe very small distances. For this we require beams of light which can be focussed to very fine beams.
The focusing of an electromagnetic beam depends on the wavelength of the light that we are using. If the wavelength of given radiation is very small then we can focus that light to very fine beams as compared to a radiation which has larger wavelengths.
Now we know that we require electromagnetic radiation which has the smallest wavelength in the electromagnetic spectrum. But we also need to take care of the fact that those radiation do not have any side effects like being hazardous to the human body. Based on this reasoning, the best type of radiation is the ultraviolet rays. These rays have small wavelengths and are widely used in precision applications like LASIK eye surgery.
Hence, the correct answer to the question is the option B.

Note:
X-rays have smaller wavelengths then the ultraviolet waves but still not used for above application. The reason for this is that X-rays have very high penetrating power and long exposures to this radiation can be hazardous to health. Same is the case with gamma radiation which is even more harmful then x-rays.