Which one of the following statements is not correct ?

[amp_mcq option1=”The longest wavelength of light visible to human eye is about 700 nm” option2=”The shortest wavelength of light visible to human eye is about 400 nm” option3=”The wavelength of gamma rays is longer than that of X-rays” option4=”The ability of a telescope to form separable images of close objects is called its resolving power” correct=”option3″]

This question was previously asked in

UPSC NDA-2 – 2016

Download PDF Attempt Online

The electromagnetic spectrum is ordered by wavelength (or frequency/energy). Moving from shorter wavelengths to longer wavelengths, the order is typically Gamma rays, X-rays, Ultraviolet, Visible light, Infrared, Microwaves, Radio waves. Therefore, gamma rays have shorter wavelengths than X-rays. The statement that the wavelength of gamma rays is longer than that of X-rays is incorrect.

Order of electromagnetic spectrum components by increasing wavelength: Gamma < X-ray < UV < Visible < IR < Microwave < Radio.

Statements A and B are correct descriptions of the approximate range of wavelengths for visible light, with red light (around 700 nm) having the longest wavelength and violet light (around 400 nm) having the shortest. Statement D provides a correct definition of resolving power, which is an important characteristic of optical instruments.

More similar MCQ questions for Exam preparation:-