Question

The cause of twinkling of stars is:

• A. Dispersion
• B. Scattering
• C. Atmospheric refraction
• D. Reflection

Hint:

Twinkling of stars is primarily caused by atmospheric refraction, which bends light as it passes through Earth's atmosphere. The varying density of the atmosphere causes the light path to change, leading to fluctuations in the star's apparent brightness and position.

Answer 1

The Correct Option is C

Step 1: Understand Twinkling of Stars.
Twinkling, or scintillation, is the apparent fluctuation in the brightness and position of stars when viewed from Earth. This phenomenon occurs due to the bending of light as it passes through Earth's atmosphere. The key factors involved are: 1. Dispersion:
Dispersion refers to the splitting of light into its component colors due to differences in refractive indices. While dispersion affects the color of light, it is not the primary cause of twinkling. 2. Scattering: - Scattering occurs when light interacts with particles in the atmosphere, causing it to spread out in different directions. While scattering can affect the overall brightness of stars, it is not the main cause of twinkling. 3. Atmospheric Refraction:
Atmospheric refraction is the bending of light as it passes through Earth's atmosphere. The density of the atmosphere varies with altitude, causing light from stars to bend as it travels through different layers. This bending causes the starlight to appear to "twinkle" because the path of light changes slightly due to turbulence in the atmosphere. 4. Reflection:
Reflection involves light bouncing off surfaces. While reflection can occur in certain atmospheric conditions, it is not the primary cause of twinkling. Step 2: Analyze Each Option.
Option (1): Dispersion — Incorrect, as dispersion does not directly cause twinkling.
Option (2): Scattering — Incorrect, as scattering is not the primary cause of twinkling.
Option (3): Atmospheric refraction — Correct, as this is the primary cause of twinkling.
Option (4): Reflection — Incorrect, as reflection is not the primary cause of twinkling.
Step 3: Final Answer. $$ (3) \mathbf{\text{Atmospheric refraction}} $$