Class 6 Science Chapter 7 MCQ

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

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.

Time of the first bell in the school does not express a time interval because it has only a single value of time, while the other quantities like a day, a second and a school period can be divided into a number of shorter periods of time. Note: A time interval should have at least two values of time.

We have to convert the height of 1.56 m into mm. Now, we know that: 1 meter = 1000 mm So, 1.56 m = 1000 x 1.56 mm = 1560 mm Thus, a height of 1.56 m is equal to 1560 millimeter

Motion in a straight line is called rectilinear motion. Some examples of rectilinear motion are motion of a vehicle on a straight road, motion of a train on a straight track, motion of a falling stone, motion of a ball rolling on ground etc. Rectilinear motion takes place in a fixed direction.

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.

A communication satellite is stationed in an orbit high above the earth which shows three types of motion rotational motion, periodic motion and circular motion but not exhibit rectilinear motion.

As we know that: 1000 meter makes 1 kilometer 1 meter = 1/1000 kilometer 1425 meter = 1/1000 x 1425 kilometer = 1.425 kilometer Thus, a distance of 1425 meter is equal to 1.425 kilometer.

A pencil or a notebook has small length which is much smaller than a meter. It is inconvenient to express such a small length in terms of meter. So, the length of small objects is measured in centimeter. Thus, in order to measure the length of a pencil or notebook, we use centimeter as the unit of length. A centimeter is one-hundredth of a meter.

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

If we consider a merry-go-round as a whole, then it shows rotational motion because it turns on an axle. But the outer part of merry-go-round (on which children sit) shows circular motion. So, a merry-go-round has two types of motion at the same time, rotational motion and circular motion.

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

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.

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

The various types of devices which are commonly used for measuring length are meter scale and measuring tape. If the object is round then we have to use a measuring tape for making measurement of length. As the girth of a tree can be measured only by using a measuring tape because a measuring tape can be bent around the tree. And plastic ruler, a meter scale or a meter rod is made of metal and cannot be bend at all.

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 circular motion and object as a whole travel along a circular path but in rotational motion the object spins on its axis.

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

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.”

The screw undergoes two kinds of motion that is periodic motions and circular motion.

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

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

The process of finding an unknown quantity by comparing it with a known fixed quantity of the same kind, called measurement. And unit of measurement accepted universally, called the standard unit. But when we guess the amount of anything without actual measurement, called “Estimation”.