universe & solar system section 10 MCQ Questions & Answers Detailed Explanation

Answer: (c)

Answer: (a)

The word “pulsar” is a contraction of “pulsating star. A pulsar is formed when a massive star collapse exhausts its supply of fuel. It blasts out in a giant explosion known as a supernova, the most powerful and violent event in the universe.

Without the opposing force of nuclear fusion to balance it, gravity begins to pull the mass of the star inward until it implodes.

In a pulsar, gravity compacts the mass of the star until it forms an object composed primarily of neutrons packed so tightly that they no longer exist as normal matter.

As the star collapses, it begins to spin more rapidly in what is known as the conservation of angular momentum. The process is similar to that of an ice skater pulling their arms in close to spin faster. What is left behind is a rapidly spinning ball of tightly packed neutrons inside an iron shell.

Answer: (a)

Neutron star is also known as Pulsar. A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star.

Answer: (c)

The shortest ditance between two places on the earth surface is along the Great Circles. The property of a great circle is that a plane passed along it passes through the centre of the earth and divides it into two equal parts or hemispheres. Among the latitudes only the equator is a great circle while among longitudes all of them are great circles.

Answer: (b)

Answer: (d)

Venus is smaller in size than the Earth. Diameter of earth is12,742 km while that of Venus is 12,100 km