Class 6 Science Chapter 10 MCQ

The SI unit of measuring length is meter. 10,00,000 millimeter makes 1 kilometer. 1,00,000 centimeter makes 1 kilometer. 1,000 meter makes 1 kilometer. Thus, millimeter is the smallest unit of length and kilometer is the largest unit of length. But the SI unit of measuring length is “meter”. Note: When we measure the distance between celestial bodies (stars, galaxy, asteroids etc.) we use light year.

Motion in a straight line is called rectilinear motion. In other words, when an object moves along a straight-line path it is called rectilinear motion. The motion will not be exhibited by the moon moving around the earth is rectilinear motion. And rest of three motions are exhibit by the moon.

When an object turns or spins about a fixed axis, it is called rotational motion. When an object moves along a straight-line path it is called rectilinear motion. When a bicycle moves on a straight road, turning of bicycle wheel shows the rotational motion. And as it goes in a straight road, it exhibits the rectilinear motion.

Since, ribbon is folded 5 times, Length of ribbon = (27.5 – 2) cm x 5 = (25.5 x 5) cm = 127.5 cm = 1.27 m 1.27 m lies in the range of 1.25 m – 1.35 m.

We know that, 1 hour = 60 x 60 = 3600 seconds (Thus, 1 minutes = 60 seconds and 60 minutes make an hour) 24 hour = 3600 x 24 = 86,400 seconds

In ancient times, people used boats for transport along water routes such as rivers or any water sources. Initially the boats were simple logs of wood in which a hollow cavity was made for people to sit and carry goods.

The earth moves around the sun, so it has circular motion. The earth repeats its motion around the sun after regular intervals of time (means one year), so it has periodic motion and the earth rotates on its axis, so it has also rotational motion. Thus, the earth has three types of motion at the same time, circular motion, periodic motion and rotational motion.

In the beginning of 19th century, the invention of steam engine introduced a new source of power to run transport vehicles. Steam engines were used to pull trains on railroads or railway tracks for carrying people and goods from one place to another. Steam engines were also used to run ships in the beginning. The steam engine is called external combustion engine because the fuel or coal for making steam was burnt outside the engine.

The compass was invented in China during the Han Dynasty between the 2nd century BC and 1st century AD where it was called the “south-governor”. The Chinese first used compasses not for navigation, but for spiritual purposes. They used the magnetic devices to organize buildings and other things according to feng shui, the ancient practice of harmonizing an environment according to the “laws of Heaven.”

Here, are all the statements are correct. Hence, your answer will be option [D].