i. A vector drawn from the centre of a circle to position of a particle on circumference of circle is called as ‘radius vector’.
ii. It is given by,
\(|\vec r|=\cfrac{\delta s}{\delta \theta}\)
where, δs = small linear distance
δθ = small angular displacement
iii. It is directed radially outwards.
iv. Unit: metre (m) in SI system and centimetre (cm) in CGS system.
v. Dimensions: [M0 L1 T0 ]
