METHOD OF MEASUREMENT OF DIFFERENT METHOD OF MEASUREMENT OF DIFFERENT PHYSICAL QUANTITIES

Method for the measurement of length with the help of ordinary scale.

Ordinary scale is a device used to measure the length of an object. 
Ordinary scale is generally made up by wood, metal or plastic. It is graduated in centimeters, millimeters. 1 centimeter is divided into 10 equal parts, each part is 1 millimeter.  
To measure the length of a line say AB, we place the scale in such a way that it remains perpendicular to the line AB. Now note the reading of the starting point and the end point B from the scale.
Then, Length of line AB = Reading of end B – Reading of end A
As  per example: Let the starting point A of the line AB is at 2 cm, coincide with the scale. If the end point B of the line does not coincide exactly with the graduation of the scale, the reading has to be taken by eye approximation method. While taking the reading  eye should be placed directly above the point B. Let the end B coincide with the scale at 6.5 cm .
 Therefore length of the line AB = 6.5cm -2cm = 4 .5 cm.

Method for the measurement of mass with the help of a common balance

Common balance is an instrument used to measure the mass of a body. 
By common balance we find the mass of a body by comparing its mass with some known standard weights. Generally we put the body on the left pan of the balance whose mass is to be determine and the standard weights are placed on the right pan. When the beam of the balance becomes horizontal then the mass of the body is equal to the standard weight. 

Method for the measurement of mass with the help of a spring balance

Spring balance is a type of balance used to measure the weight of a body.
It consists of a spring kept in a metal tube. It is partially exposed in front of the metal tube. The upper end of the spring is rigidly fixed. The lower end of the spring is attached with a metal rod. One hook is attached with the lower end of the metal rod. The body whose weight is to be determined is hanged from this hook. A pointer attached to the spring moves on a graduated scale (usually in grams or kilograms and grams ). The position of the pointer indicates the weight of the body.