The red colour in a rainbow will be seen when the angle between a beam of sunlight and light sent back by a raindrop ………………….

A rainbow can be observed when there is a light shower with relatively large raindrop occurring during morning or evening time with enough sunlight around.

C) A + d = i1 + i2 

Correct option is  D) 0° to 42°

Correct option is  B) 40°

A) low refractive index

Correct option is (B)water droplets

i. For clear visibility of rainbow, a beam must have enough intensity. ii. The curve for angle of deviation and angle of incidence is almost parallel to X-axis near minimum deviation...

a1 = 1.5 a2 To find: \(\frac{I_1}{I-2}\) Formula: I ∝ a2 Calculation: From formula, \(\frac{I_1}{I_2}=(\frac{a_1}{a_2})^2=(\frac{1.5_{a_2}}{a_2})^2\) = (1.5)2 = 2.25

a1 = 2.5 a2 To find: \(\frac{I_1}{I-2}\) Formula: I ∝ a2 Calculation: From formula, \(\frac{I_1}{I_2}=(\frac{a_1}{a_2})^2=(\frac{2.5_{a2}}{a_2})\) = (2.5)2 = 6.25

C) Silver bromide