Physics XI Content
Scalar and Vector – Introduction
|Physical quantities which can completely be specified by a number (magnitude)|
having an appropriate unit are known as “SCALAR QUANTITIES”.
Scalar quantities do not need direction for their description.
Work, energy, electric flux, volume, refractive index, time, speed, electric potential, potential difference, viscosity, density, power, mass, distance, temperature, electric charge, electric flux etc.
Physical quantities having both magnitude and direction
We can’t specify a vector quantity without mention of direction.
Velocity, electric field intensity, acceleration, force, momentum, torque, displacement, electric current, weight, angular momentum etc.
REPRESENTATION OF VECTORS
On paper vector quantities are represented by a straight line with arrow head pointing the direction of vector or terminal point of vector.
A vector quantity is first transformed into a suitable scale and then a line is drawn with the help of the
scale chosen in the given direction.