Write the unit of the following fundamental quantities in S.I. system :
(i) Electric current
(ii) Plane angle
Answers
Unit of the above fundamental quantities in S.I. system are for electric current it is ampere and for plane angle it is radian.
Fundamental quantities are the quantities which cannot be derived from an other quantities and all other quantities are derived from them.these are also known as basic quantities like current, distance, time, mass etc.
S.I. unit of system which is basic and universally accepted system for fundamental quantities and is standard system of fundamental units.
Unit of following fundamental quantities are:--
(i) Electric current:-The S.I. unit of electric current is ampere represented by A
- One ampere is that constant current which if maintained in two straight parallel conductors of infinite length and are 1 meter apart in vacuum, would produce force of 2*10^-7 newton per metre of length.
(ii)Plane angle:-The S.I. unit of plane angle is radian symbol is rad.
- It is defined as the plane angle subtended at the centre of circle by an arc equal in length to the radius of the circle.
- So radian= arc/radius= l/r
SI unit of electric current and plane angle:
• The SI unit of electric current is the ampere, which is the movement of electric charge across a surface at the rate of one coulomb per second.
• SI unit of plane angle is referred to as radian. A radian is a unit of degree for angles used chiefly in trigonometry. It is used as an alternative of degrees.