Science [1 Marks Each] M.C.Q.

National Physical Laboratory

It is a periodic motion.

Metre is a standard unit of measurement.

Apple falling from a tree and motion of a car on road are the examples of rectilinear motion

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”.

Measurement is the comparison of an unknown quantity with a known quantity.

A measuring tape uses standard units of measurement for measuring length. Hence, Somus teacher asked him to measure the length of the table by using a measuring tape.

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.

Here, are all the statements are correct. Hence, your answer will be

Fixed quantity used for measurement.

The fan merely rotates about a fixed axis. But the different points (particles) of its blades describe circular motion. During the rotation/the different particles cover equal distances in equal intervals of time exhibiting periodic motion

The thickness of a coin can be measured in millimetres.

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.

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.

The distance between Delhi and Mumbai is expressed in kilometre because other units like metre, centimetre and decametre are so small to express this big distance.

Motion of a vehicle on a straight road is not rectilinear motion.

Quintal.

All the above.

Here, are all the statements are correct. Hence, your answer will be

Raju covers a longer distance with a higher speed as compared to Prem.

Non-uniform motion.

Periodic motion.

When the string of a violin stretched between two fixed points is plucked in the middle, it starts moving up and down. However, the motion is not oscillatory in nature because the whole string does not move up and down. Such a motion is called vibratory motion.

Kilometre is a larger unit.

The membrane of a drum vibrates up and down exhibiting oscillatory motion.

Mechanics is the study of body at rest and in motion.

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.

All other are multiples of metre.

A rider on horse falls back when horse starts running, all of a sudden because the rider is in state of rest initially and later inertia of rest keeps the upper part of body at rest while lower part of the body moves forward with horse.