The one parameter that determines the brightness of a light source sensed by an eye is

Answer: The color of leaves on a plant is dependent on the type of chlorophyll present in them. Explanation: Chlorophyll is an important pigment in the process of photosynthesis. Chlorophyll A is the most common...

When certain metals like magnesium, aluminium, etc., are exposed to air, they form an oxide film on their surface. Thus, the surface lose its brightness when kept in air for a...

(i) (a) cornea allows the light to enter the eye. (b) Ciliary muscles help in changing the focal length of the eye lens. (ii) The image formed is Real, inverted and diminished

(a) far away from the eye

The correct answer is (a) =x

Overall luminous efficiency =Total luminous flux / Power input =35x685/100 = 239.75 lumen/W

(c) depends on its power (d) depends on the wavelength emitted.

(a) Albedo is the fraction of the incident sunlight that is reflected. When an object reflects most of the light that hits it and looks bright then it has high...

(c) Generally blindness is caused by the dryness and hardness of cornea. Cornea is a clear layer which helps passing of light. It is an outer layer and can be...

(c) Campbell - Stoke’s recorder