The Universe (Part-2)

Total Questions: 50

41. Seasonal changes are caused by which one of the special characteristic of Earth's motion? [R.A.S./R.T.S. (Pre) 1992]

Correct Answer: (c) (a) and (b) both
Solution:The biggest reason for seasonal changes is Earth's axial tilt by 23½ degrees and Earth's revolution around Sun. The variability of the distance of Earth from Sun has also slight importance in regard to seasonal variability.

42. What causes the change of Seasons? [Jharkhand P.C.S. (Pre) 2013]

Correct Answer: (c) Earth's Revolution and inclination of its Axis
Solution:The biggest reason for seasonal changes is Earth's axial tilt by 23½ degrees and Earth's revolution around Sun. The variability of the distance of Earth from Sun has also slight importance in regard to seasonal variability.

43. Consider one special point at the Earth's surface (eg. City Delhi) its temperature at noon (eg. 12 O'clock) will be higher in Summer in comparison to winter because- [I.A.S. (Pre) 1993]

Correct Answer: (b) In winter the Sun rays falling on the Earth bends more towards the Earth's surface in Comparison to the summer.
Solution:Twice in a year on 21 March and 23rd September, Sun rays fall perpendicular on the Earth at the Equator. From 21" March to 23rd September, the Sun stands between the Equator and Tropic of Cancer.

In the same period, summer season occurs in North hemisphere and winter occurs in the South hemisphere. The sunrays fall in askew position in South hemisphere than in North hemisphere, while opposite to it from 23 September to 21 March the Sun stands between Equator and Tropic of Capricorn.

In this period, the Sun rays fall in more askew position in North hemisphere than in South hemisphere and summer occurs in South hemisphere and winter occurs in North hemisphere. Due to this process, the temperature of Delhi, situated in North hemisphere; remains higher in summer season as compared to winter season.

44. If the distance between the sun and the earth is reduced by quarter to present distance, then probability of which one will increase - [R.A.S./R.T.S. (Pre) 1993]

Correct Answer: (c) The duration of our year will be decreased.
Solution:If the distance between Sun and Earth is reduced by quarter to present distance, then the size of Earth's orbit in which it revolves around the Sun will be smaller and consequently the duration of the year would be less than 365.25 days.

Due to the reduction in present distance, the speed with which Earth is revolving will increase.

45. Consider the following statements: [I.A.S. (Pre) 2002]

Assertion (A): Artificial satellites are always launched from the earth in the eastward direction.

Reason (R): The earth rotates from west to east and so the Satellite attains the escape velocity.

Code:

Correct Answer: (d) (A) is false, but (R) is true.
Solution:It is true that most satellites are launched in the east direction from Earth because satellites get momentum but it is not true for every satellite launch. Satellite to orbit poles is launched in the direction of north or south.

The Earth's rotation adds a small amount of initial velocity, but the rocket's engines are what provide the necessary speed to overcome Earth's gravity. The Earth rotates from west to east, and this rotation imparts a certain speed to any point on its surface.

Launching a satellite eastward takes advantage of this pre-existing motion, requiring less fuel to reach the necessary orbital velocity. Escape velocity is the minimum speed an object needs to escape the gravitational pull of a planet, or in this case, the Earth.

46. A Ball thrown outside from an artificial satellite revolving around the Earth will [U.P.P.C.S. (Pre) 1995]

Correct Answer: (d) Revolve around the Earth in the same orbit with the same time period as satellite
Solution:Any object thrown out of artificial satellite will revolve around like the satellite. It is due to the principle of inertia and the Earth's gravitational pull. The Earth's gravity will continue to pull the object towards the Earth, but because of the object's initial velocity, it will follow a curved path, essentially orbiting the Earth.

Eventually, if the object is in a low orbit, it will encounter atmospheric drag, which will cause it to lose altitude and eventually burn up in the atmosphere.

47. Which elements are abundant in the formation of interior layer of the earth? [67th B.P.S.C. (Pre) (Re. Exam) 2022]

Correct Answer: (d) Nickel and ferrum
Solution:The elements nickel and ferrum are abundant in the formation of Nife, the inner layer of the Earth. Nife is abbreviation of Nickel and Ferrum (Iron). The early core was formed when droplets of iron, nickel, and other heavy metals gravitated to the Earth's center to form the core of the new planet.

Relatively buoyant materials, such as silicates, and water, stayed close to the planet's exterior. This process is known as planetary differentiation. The molten material that surrounded the core was the early mantle.

Materials that initially stayed in their liquid phase during this process, called "incompatible elements," ultimately became Earth's brittle crust. The crusts are still evolving due to plate tectonics. Water held within minerals erupted as lava, a process known as "outgassing." As more water was expelled, the mantle solidified.

48. In the structure of planet Earth, below the mantle, the core is mainly made up of which one of the following? [I.A.S. (Pre) 2009]

Correct Answer: (c) Iron
Solution:There is an outer core and inner core below the mantle in the structure of the earth. The outer core is about 2260 Km thick (radius) and mostly composed of liquid iron and nickel. The Inner core is a hot dense ball of (mostly) Iron. It has a radius of about 1220 km.

49. The World Earth Day is celebrated on [M.P.P.C.S. (Pre) 2015]

Correct Answer: (a) 22 April
Solution:Earth Day is celebrated on 22nd April every year to mark the birth Anniversary of Modern environmental movement in 1970. It was the first time celebrated in the year 1970.

The concept of Earth Day can be traced back to the late 1960s, which saw a surge in public debate over environmental issues, with Rachel Carson's influential book Silent Spring (1962) and the Santa Barbara oil spill (1969) raising awareness about environmental destruction.

The first World Earth Day was held on April 22, 1970, in the United States. It was organized by a group of environmental activists led by US Senator Gaylord Nelson, who was concerned about the negative impact of industrialization and pollution on the environment.

Since then, it has become a global movement that encourages individuals and communities to take action towards protecting our planet.

50. When is the 'International Earth Day' celebrated? [M.P. P.C.S. (Pre) 2018]

Correct Answer: (c) 22nd April
Solution:Earth Day is celebrated on 22nd April every year to mark the birth Anniversary of Modern environmental movement in 1970. It was the first time celebrated in the year 1970.

The concept of Earth Day can be traced back to the late 1960s, which saw a surge in public debate over environmental issues, with Rachel Carson's influential book Silent Spring (1962) and the Santa Barbara oil spill (1969) raising awareness about environmental destruction.

The first World Earth Day was held on April 22, 1970, in the United States. It was organized by a group of environmental activists led by US Senator Gaylord Nelson, who was concerned about the negative impact of industrialization and pollution on the environment.

Since then, it has become a global movement that encourages individuals and communities to take action towards protecting our planet.