Question

Which of the following statement is correct?

• A. At sunset of sunrise, the sun’s rays have to pass through a small distance in the atmosphere.
• B. At sunset or sunrise the sun’s rays have to pass through a larger distance in the atmosphere.
• C. Rayleigh scattering which is proportional to
• D. Most of the blue and other shorter wavelength are not removed by scattering.

Answer 1

Answer: (A)

At sunset of sunrise, the sun’s rays have to pass through a small distance in the atmosphere.

Answer 2

Two waves of a single source having an amplitude A interfere. The resulting amplitude

where A₁ = A₂ = A and δ = phase difference between the waves

⇒ I_r = I₁ + I₂ + 2

When the maxima occurs at the center, δ = 0

⇒ …(1)

Since the phase difference between two successive fringes is 2π, the phase difference between two points separated by a distance equal to one quarter of the distance between the two, successive fringes is equal to

δ = (2π ) $\left( \frac { 1 } { 4 } \right) = \frac { \pi } { 2 }$ radian

⇒ $\mathrm { I } _ { \mathrm { r } _ { 2 } } = 4 \left| \cos ^ { 2 } \left( \frac { \pi / 2 } { 2 } \right) = 2 \right|$ …(2)

using (1) and (2),