Physics
Assertion (A) : Tiny air molecules scatter blue light more than red light.
Reason (R) : The refractive index of a medium is greater for blue light than red light.
- (A) is true but (R) is false.
- (A) is false but (R) is true.
- Both (A) and (R) are true and (R) is correct explanation of (A).
- Both (A) and (R) are true and (R) is not the correct explanation of (A).
Answer
Both (A) and (R) are true and (R) is not the correct explanation of (A).
Explanation:
Assertion is true because blue light has a shorter wavelength than red light, so it is scattered more by tiny air molecules. Reason is also true because the refractive index of a medium is greater for blue light than for red light. However, scattering depends mainly on wavelength and not on refractive index.
Therefore, both (A) and (R) are true, but (R) is not the correct explanation of (A).
Related Questions
A fast-moving cyclist stops pedalling on reaching a hilly track. If he continues to move with the acquired energy, then assuming no loss of energy:
- his kinetic energy remains constant at all times.
- his potential energy remains constant at all times.
- his total mechanical energy continuously increases.
- his total mechanical energy remains constant.
The distance (V) of a virtual image formed by a lens of focal length 15 cm never exceeds a certain finite value, then this value will be:
- less than 15 cm
- between 15 cm to 30 cm
- less than or equal equal to 30 cm
- less than or equal to 15 cm
In the circuit given below, identify the lamp (L1, L2, L3 and L4) whose failure would not interrupt the power supply to the other lamps.

- L1
- L2
- L3
- L4
Equal volumes of water are added to three cylindrical jars A, B and C of same height and radii rA, rB and rC respectively with rB < rA < rC. If you blow air into the mouth of these jars, which tube will produce the shrillest note?
- A
- B
- C
- All will produce the notes of same shrillness