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

Answer: (b)

Answer: (b)

A nautical mile is based on the circumference of the planet Earth. If you were to cut the Earth in half at the equator, you could pick up one of the halves and look at the equator as a circle. You could divide that circle into 360 degrees.

You could then divide a degree into 60 minutes. A minute of arc on the planet Earth is 1 nautical mile. A nautical mile is1.1508 miles or 6,076 feet.

Answer: (d)

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: (c)

Answer: (a)