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Chapter— 2, nits and M remen, , 1. What is, quantities?, , meant by Physical, , Ans: The quantities which can be, measured directly or indirectly are, called physical quantities., , 2. Which are the two types of physical, quantities? Explain., , Ans: There are two types of physical, quantities:, , a) Fundamental Physical, quantities (Basic physical, quantities), , The physical quantities which are, independent of each other and cannot, be expressed in terms of other physical, quantities, physical quantities., , There are seven fundamentai or basic, quantities. They are:, , i. Mass, , ii. Length, , iii. Time, , iv. Electric current, , vy. Temperature, , vi. Luminous intensity, , Amount of substance., , b) Derived Physical quantities, The physical quantities which can, be expressed in terms of fundamental, physical quantities are called derived, quantities., Eg: - Velocity, Acceleration, Force,, Momentum etc., , 3. Define Physical unit., , are called fundameatal |, , , , Ans: The standard amount of a, physical quantity chosen to measure, the quantity of the same kind is called, a physical unit., 4. What is meant by a unit system?, Explain some commonly used unit, systems., Ans: A complete set of units which is, used to measure all kinds of, fundamental and derived quantities is, called a system of units., Some of the commonly used unit, systems are as follows:, iC. G. S. System, It was set up in France, Least céntimetre,, Mass.— gram, Time = second, / iL. P.S. System, | (It is a British system, Length — foot, Mass — pound, Time - second, iii.M. K. S. System, It is also a French system, Length — metre, Mass — kilogram, Time — second, iv.S.1. System, It is the international system of units., SI is the abbreviation for “Systeme, Internationale d’ Unites”, SI system is based on 7 fundamental, , units and two supplementary units., , 7 Fundamental units, , i.Length — metre (m), , ii.Mass — kilogram (Kg), iii. Time — second (S), iv. Temperature — Kelvin (K), v.Electric current — ampere (A), vi.Luminous intensity — candela (Cd), vii. Amount of substance — mole (mol)