Question

Assertion: The colour of the green flower seen through red glass appears to be dark.
Reason: Red glass transmits only red light.
A) Assertion is true and reason is the correct explanation of assertion.
B) Assertion is true but reason is not the correct explanation of assertion.
C) Assertion is true but reason is false.
D) Assertion is false but reason is true.

Answer 1

Hint: The above question is based on the reflection and abortion of light having different wavelengths. Red colour has the maximum wavelength as per the distribution of white light (seven colours) and green light has the wavelength somewhat lesser than red light. Colour of the objects around us depends upon the colour they reflect.

Complete step by step solution:
Things around us have some or the other colour, which is only due to the colour of light they reflect to our eyes which we see. Light first touches the object and then the retina of our eye; we are watching objects because they are reflecting light and this reflected light passes through the pupil and lens of the eye after that retina of the eyes.

Every object reflects or absorbs light in different ways. If we say a ball is red this means that the colour of the ball reflects only red colour and absorbs all other colours falling on it; the receptors of our eyes then become sensitive to red colour thus we see red colour.

In the similar way when a green colour flower is seen in the red light glass, the petals of the flower absorb red light and reflect a very little light in return which seems negligible to our eyes. Secondly, red glass transmits only red light no other colour, thus the flower appears dark to us.

Thus the assertion and reason are both true option (A) is correct.

Note: Reflection and abortion are a very good example of solar cookers. Generally we have seen the solar cookers which were made to cook food or heat water are painted with black colour because black colour absorbs all the light falling on it and gives zero reflection. This is the reason food can be cooked and food can be heated with maximum heat.