NEET
- Exam
- NEET
- Subject
- Physics
- Chapter
- Electromagnetic Waves
NEET · Physics · Electromagnetic Waves
Given below are two statements: one is labelled as Assertion (A)...
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Infrared waves are often referred to as heat waves.
Reason (R): They are produced by the vibration of atoms and molecules, and their absorption by water molecules in materials increases thermal motion.
In the light of the above statements, choose the most appropriate answer from the options given below:
Assertion (A): Infrared waves are often referred to as heat waves.
Reason (R): They are produced by the vibration of atoms and molecules, and their absorption by water molecules in materials increases thermal motion.
In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is not correct
- D(A) is not correct but (R) is correct
Correct answer
A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
Step-by-step solution
Infrared waves are produced by hot bodies and molecules due to the vibration of atoms and molecules.
They are commonly known as heat waves because water molecules (and other molecules like , ) present in most materials readily absorb infrared waves.
Upon absorption, the thermal motion of these molecules increases, which causes the material to heat up.
Therefore, both Assertion (A) and Reason (R) are correct, and (R) provides the correct physical explanation for why they are called heat waves.
Answer: Both (A) and (R) are correct and (R) is the correct explanation of (A)
They are commonly known as heat waves because water molecules (and other molecules like , ) present in most materials readily absorb infrared waves.
Upon absorption, the thermal motion of these molecules increases, which causes the material to heat up.
Therefore, both Assertion (A) and Reason (R) are correct, and (R) provides the correct physical explanation for why they are called heat waves.
Answer: Both (A) and (R) are correct and (R) is the correct explanation of (A)