The correct answer is A. two internal refractions before emerging out of the drop.
A rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth’s atmosphere. Rainbows can be full circles. However, the observer normally sees only an arc formed by illuminated droplets above the ground, and centered on a line from the Sun to the observer’s eye.
The rainbow is caused by the refraction of light in the water droplets. When sunlight hits a water droplet, it is refracted (bent) as it enters the droplet. The light is then reflected off the back of the droplet and refracted again as it exits the droplet. The angle of refraction depends on the wavelength of the light, which is why we see a spectrum of colors in the rainbow.
The primary rainbow is the brightest and most common type of rainbow. It is formed when sunlight is refracted twice in a water droplet and then reflected once. The secondary rainbow is fainter than the primary rainbow and is formed when sunlight is refracted twice in a water droplet and then reflected twice.
The primary rainbow is formed when light suffers two internal refractions before emerging out of the drop. The first refraction occurs when light enters the drop from the air. The light is then reflected off the back of the drop and refracted again as it exits the drop. The angle of refraction depends on the wavelength of the light, which is why we see a spectrum of colors in the rainbow.
The secondary rainbow is formed when light suffers four internal refractions before emerging out of the drop. The first refraction occurs when light enters the drop from the air. The light is then reflected off the back of the drop and refracted again as it exits the drop. The light is then reflected off the back of the drop again and refracted again as it exits the drop. The angle of refraction depends on the wavelength of the light, which is why we see a spectrum of colors in the rainbow.
The secondary rainbow is fainter than the primary rainbow because the light has to travel through the drop twice. The light also loses some of its energy each time it is refracted.