Question

Assertion : X-rays are used for studying the structure of crystals.

Reason : Size of the atoms of crystals is of the order of wavelength of X-rays.

• A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion
• B. If both Assertion & Reason are True & the Reason is not a correct explanation of the Assertion
• C. If Assertion is True but the Reason is False
• D. If both Assertion & Reason are false

Answer 1

The correct option is A

If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion

Explanation for Assertion :

1. The distance between the atoms of crystals is of the order of the wavelength of X− rays. when they fall on a crystal, they are diffracted.
2. The diffraction pattern is helpful in the study of crystal structure.

Explanation for Reason :

1. Interatomic spacing in a crystal acts as a diffraction grating.
2. Crystals are regular arrays of atoms, and X-rays can be considered waves of electromagnetic radiation.
3. X-rays are used to produce the diffraction pattern because their wavelength $\lambda$ is typically the same order of magnitude (1–100 Ă) as the spacing d between planes in the crystal.

Here, Assertion & Reason are True & the Reason is a correct explanation of the Assertion

Hence option A is correct.