Question

what isthe working principles of a spring balance

Answer 1

Spring balances or spring scales calculate mass by first measuring weight by balancing the force due to gravity against the force on a spring, whereas a balanceor pair of scales using a balance beam compares masses by balancing the weight due to the mass of an object against the weight of one or more known mass

Answer 2

A spring scale or spring balance or newton meter is a type of weighing scale. It works by Hooke's Law, which states that the force needed to extend a spring is proportional to the distance that spring is extended from its rest position. Therefore, the scalemarkings on the spring balance are equally spaced.