Identify the correct statement/s regarding phases of moon. (A) We see only that part of the moon from which the light of the sun is reflected towards us. (B) Moon revolves around the Earth and the earth blocks the sunlight falling on it which results in phases. (C) Phases of moon are caused due to varying velocity of moon around the earth. (D) The size of the illuminated part of moon visible from earth increases after new moon day.
(A) and (D)
Statement (A) is correct: the moon does not emit its own light — we see only the portion of the moon's surface that reflects sunlight towards the Earth, and this visible lit fraction changes as the moon orbits the Earth, giving rise to phases.
Statement (B) is incorrect: the phases of the moon are not caused by the Earth blocking sunlight falling on the moon — that describes a lunar eclipse, which is a separate, much rarer event. Phases occur because of the changing relative positions of the Sun, Earth, and Moon as the Moon revolves around the Earth.
Statement (C) is incorrect: the moon's orbital velocity around the Earth does not vary enough to be the cause of phases; phases depend on the angle between the Sun, Earth, and Moon, not on the moon's speed.
Statement (D) is correct: after the new moon day, the moon enters its waxing phase, during which the illuminated part of the moon visible from Earth keeps increasing day by day until it becomes a full moon.
Hence, statements (A) and (D) are the correct statements.
Important Questions from Gravity
Which of the following statement is correct?
I. Gravitation is a weak force unless large masses are involved.
II. The weight is equal to the product of mass and acceleration due to gravity.
What is the reason that the value of g (acceleration due to gravity) becomes greater at the poles than at the equator?
If the acceleration due to gravity on the surface of earth is g, then the acceleration due to gravity on the surface of a planet whose mass is same as that of earth and radius is twice as that of earth is ___________.
A man's mass is 72 kg on the earth. His mass on the moon will be:
At which of the following place, weight of an object is maximum?
