Measurement Online Test 6th Science Lesson 1 Questions in English

The comparison of unknown quantities with some known quantities is known as measurement. Measurement of a quantity has two parts: a number and its unit.

The distance between one end and the other desired end is called as length. It may be the distance between the edges of a book or a table or the corners of a football ground or even from your home to school.

The standard unit of length is 'Metre'. It is represented by letter ‘m’. Very small lengths can be measured in mm and cm. Still larger measures, say height of a building, a banner or a lamp post are all measured in metre.

Know the unit of length 1 km (kilometre) = 1000 m (metre) 1 m (metre) = 100 cm (centimetre) 1 cm (centimetre) = 10 mm (millimetre).

The sake of uniformity, scientists all over the world have adopted a common set of units to express measurements. This system is called as the International System of Units or SI Units.

SI unit for length is Metre SI Unit for mass is Kilogram SI Unit for time is Second.

Area of Surface = m2 Volume of Solid = m3

Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight.

Correct position of the eye is also important for taking measurement. Your eye must be exactly in front of vertically above the point where the measurement has to be taken.

Length is a fundamental quantity. That means, it connot be expressed in any other quantities. Using length, we can find out other measurements like Area and Volume. Area is obtained by using two lengths. So, Area = Length × Breadth.

Volume is also a derived quantity and it can be measured from measuring lengths.

To know the volume of a box we need to know the length (l), breadth (b) and height (h). With a measuring scale measure the three parameters in cm. The volume of the box = l × b × h. Unit of volume would be obviously cm × cm × cm = cubic cm or cm.

Measuring the volume of a liquid is quite easy. Liquids take the shape of the container in which they are kept. A liquid whose volume is to be found can simply be poured into a graduated container.

Graduated cylinders, beakers, pipettes and burettes are available for measuring exact volumes. The volume of liquid is usually measured in litres.

As the stone is immersed, we can observe that water level increases. Why? The stone displaces the water to occupy the space inside the measuring cylinder. How much water would be displaced? It would be equal to the space taken up by stone. So the amount of water displaced will be the volume of the stone. This method is called as water displacement method.

1ml = 1 cubic cm

Gases expand to fill the container into which they are placed. When you compress, a gas you can make the same gas to occupy lesser space. (as in LPG gas cylinder). Therefore it is not easy to talk about the volume of gas in the same way as a volume of a stone or a liquid.

Mass is the measure of the amount of matter in an object. Weight is the gravitational pull experienced by the mass.

The weight is directly proportional to the mass on earths surface. On moon where the gravitational force is lesser than earth, the weight will reduce but the mass will remain same.

The moon’s gravitational pull is one sixth of the earth’s pull. Thus objects weigh six times lighter on the Moon than on the Earth.

Bigger weights are measured in tonne or Metric Tonne. 1000 milligram = 1 gram 1000 gram - 1 kilogram 1000 kilogram - 1 tonne.

We use beam balances to measure mass. A beam balance works by comparing the mass of an object to that of known mass (called a standard mass).

You can also use your pulse to measure ‘rough’ time. Count the number of pulses. That can tell you the time elapsed. In your normal speed of speaking, say “one little second”; “two little seconds” to count the passage of time.

In earlier days people used sand clock and sundial to measure the passage of time during the day. The shadow cast by a stick can be used to estimate time. One can also use a vessel with a small hole for computing time. Take a vessel or bottle with a small hole in it and fill it with water. The time taken for water to drain can also be used as a measuring device.

An odometer is a device used for indicating distance travelled by an automobile.

The metric system or standard set of units was created by the French in 1790.

A ruler or scale, used now a days to measure length was invented by a William Bedwell in 16th century.

A standard metre rod made of an alloy of platinum and iridium is placed at the Bureau of weights and measures in Paris.

One kilogram is equal to the mass of a certain bar of platinum-iridium alloy that has been kept since 1889 at the International Bureau of Weights and Measures in Sèvres, France.