universe & solar system section 3 MCQ Questions & Answers Detailed Explanation

Answer: (c)

Answer: (c)

Falls are possible only when a river is losing height suddenly. Next comes meanders. When a river reaches flatter land, flow is slowed down and meanders are formed through erosion of the river banks and deposition on the inside of bends.

Oxbow lake is formed when a wide meander is cut off from the main river, creating a free-standing body of water.

Delta is formed at the mouth of a river, where the river flows into an ocean, sea, estuary, lake, or reservoir.

Answer: (b)

Every line of longitude on a complete spherical globe in the same size, having a length equal to half the circumference of the globe on which it resides.

The actual length of a longitudinal line can be calculated by multiplying half the diameter (which is the radius of the given globe) by the value 3.14 (Pi). The equator is the circle that is equidistant from the North Pole and the South Pole.

It divides the Earth into the Northern Hemisphere and Southern Hemisphere. Of the parallels or circles of latitude, it is the longest and the only ‘great circle’.

Answer: (c)

Answer: (c)

Rejuvenation is the act of restoring to a more youthful condition.

Answer: (a)

The principle of Blackhole was enunciated by S. Chandrashekhar. A Black Hole is a region of space-time from which gravity prevents anything, including light, from escaping.

The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole, there is a mathematically defined surface called an event horizon that marks the point of no return.

The hole is called “black” because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics.