Advertisements
Advertisements
Question
What role dose infra-red radiation play in physical therapy?
Advertisements
Solution
The molecules of CO₂, NH₃ and water which are present in most materials absorb infrared waves. Due to this, the molecules heat and heat their surroundings. Hence, their thermal motion increases. Medical instruments, such as the infrared lamp which is used in physiotherapy, work on this principle.
APPEARS IN
RELATED QUESTIONS
What is the range of the wavelength of the following electromagnetic waves?
(a)X-rays,
Name the waves produced by the changes in the nucleus of an atom.
One of the following wavelengths is absent and the rest are present in the X-rays coming from a Coolidge tube. Which one is the absent wavelength?
State the name and the range of wavelength of the invisible electromagnetic waves beyond the red end of the visible spectrum.
Answer briefly.
Why high-frequency carrier waves are used for the transmission of audio signals?
Name the e.m. waves which are suitable for radar systems used in aircraft navigation. Write the range of frequency of these waves.
If the Earth did not have atmosphere, would its average surface temperature be higher or lower than what it is now? Explain.
Which of the following is a tool used for separating the different color wavelengths from each other?
Below is an incomplete table showing the arrangement of electromagnetic spectrum in the increasing order of their wavelength. Complete the table:
| Gamma ray | X - ray | UV rays | Visible rays | Infrared | A | Radio waves |
- Identify the radiation A.
- Name the radiation used to detect fracture in bones.
- Name one property common to both A and Radio waves.
