Class 6 Science Chapter 7 MCQ

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

The motion which repeats itself after regular intervals of time, is called periodic motion. When an object moves along a circular path, it is called circular motion. The movement of seconds’ hand of a watch is repeated after regular intervals of time, so the motion of seconds’ hand of a watch is an example of periodic motion. Similarly, the movement of the seconds’ hand of a watch or clock on the dial is an example of circular motion. As the watch does not move from one place to another by itself but the hands of watch or clock keep on rotating on its dial.

The distance between Delhi and Mumbai is expressed in kilometer because other units like meter, centimeter and decameter are so small to express this big distance.

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.

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.

The thickness of a coin or a thin wire is a very small length which is much smaller than even centimeter. So, it is inconvenient to express very small length in terms of centimeters. Thus, to express the thickness of a coin or a thin wire we use millimeter as the unit of length. The very small length is expressed in still smaller units called a “millimeters”.

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

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.

When a ball is moving on the ground, it is rotating as well as moving forward on the ground. So, a ball rolling on the ground has two types of motion, rotational motion as well as a rectilinear motion.

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

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].

All the reasons are correct. Hence, your answer will be option [D].

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.

The earth moves around the sun, so it has circular motion. The earth repeats its motion around the sun after regular intervals of time, 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.

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

The scientist all over the world have adopted “International System” of units or SI units which have a uniformity in the measurement of various physical quantities like length, mass and time etc. The SI unit of measuring length is “meter”. The symbol of meter is “m”. The SI unit of measuring mass is “kilogram” (kg) and the SI unit of measuring time is “second” (s)

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

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”.