Question

Wavelengths assigned to gamma rays, infra-red rays, UV rays and microwaves are 1 , 2 , 3 & 4 respectively. Then :

• A. 1 < 2 < 3 < 4
• B. 1 < 3 < 2 < 4
• C. 1 > 2 > 3 > 4
• D. 2 < 3 < 1 < 4

Answer 1

The Correct Option is B

The question is about arranging different types of electromagnetic waves in order of their wavelengths. Here, the assigned numbers represent:

• 1: Gamma Rays 
• 2: Infra-Red Rays
• 3: UV Rays
• 4: Microwaves

The electromagnetic spectrum can be arranged in increasing order of wavelength as follows:

• Gamma Rays: These have the shortest wavelengths, typically ranging from less than 10 picometers.
• UV Rays (Ultraviolet Rays): These have wavelengths between about 10 nanometers to 400 nanometers.
• Infra-Red Rays: These have wavelengths from about 700 nanometers to 1 millimeter.
• Microwaves: These have longer wavelengths, ranging from about 1 millimeter to 1 meter.

From the above arrangement, it's clear that the order of increasing wavelength is:

• Gamma Rays (1)
• UV Rays (3)
• Infra-Red Rays (2)
• Microwaves (4)

Thus, the correct order based on increasing wavelength is: 1 < 3 < 2 < 4.

This matches the given correct answer:

1 < 3 < 2 < 4