This table is explain about common misconception of measurements verses fact of the measurements 

Common Misconception

Fact

Light year is commonly understood as a unit of time

Light year is a unit of distance. One light year is the distance travelled by light through space in one year.

1 light year = 9.46x1015m

In measurement of all liquids 1kg=1 liter

Mass of liquid can be measure in kg while the volume of liquid can be measured in liter.

 

System of units

The fundamental units of length, mass and time taken are to form a system of units. For measuring various physical quantities following systems are commonly adopted.

Name of the system

Unit

Length

Mass

Time

.    FPS

foot

pound

Second

.    CGS

centimeter

Gram

second

.    MKS

meter

kilogram

second

 


Measurement of volume of irregular solids can be made as follows.

S.No

To find the volume of

Description

1.

Solids insoluble in water,

(a) But heavier than water

Take some water in a measuring jar and let its volume be v1 cm3. Immerse the solid completely in water using a string. The water level raises and let the final level be v2 cm3. So, volume of solid = (V2-V1) cm3

 

(b)Lighter than water

Let the volume of water be v1 cm3 when a sinker is immersed in it. Tie the solid to the sinker and immerse it into the water, now note the final level of water and let it be v2 cm3. Then volume of solid = (v2-v1) cm3

2.

A single drop of water

1. Take a clean burette with water. Clamp it upright.

2. Remove any air bubbles formed.

3. Now allow water to trickle slowly drop by drop, count number of drops when known volume of water has been drained out.

4. Average volume of a single drop = Volume of water drained out/number of drops

3.

Average volume of lead shots

1.Take a measuring jar with water of volume v1 cm3

2.Drop n number of lead shots into the water and note the final level of water as v2 cm3

3.Average volume of lead shot

= (v2 – v1 /n) cm3