 RRB NTPC Exam 2016 will test you on Measurement of Quantities. In physics, quantities are categorized into either scalar or vector quantities.

## RRB NTPC Exam 2016 #Daily Infographic on General Science (Physics)

There are a lot of different mathematical quantities used in physics. What is a scalar?

A scalar is a quantity that is fully described by a magnitude only. It is described by just a single number. Some examples of scalar quantities include speed, volume, mass, temperature, power, energy, and time.

What is a vector?

A vector is a quantity that has both a magnitude and a direction. Vector quantities are important in the study of motion. Some examples of vector quantities include force, velocity, acceleration, displacement, and momentum.

What is the difference between a scalar and vector?

A vector quantity has a direction and a magnitude, while a scalar has only a magnitude. You can tell if a quantity is a vector by whether or not it has a direction associated with it.

Example:

Speed is a scalar quantity, but velocity is a vector that specifies both a direction as well as a magnitude. The speed is the magnitude of the velocity. A car has a velocity of 40 mph east. It has a speed of 40 mph.

Interesting Facts about Scalars and Vectors

• Unit vectors are vectors with a magnitude of 1. They are used to define direction.
• The credit for inventing vectors is usually given to Irish physicist William Rowan Hamilton.
• Vectors and scalars are important in many fields of math and science.
• Vectors can be defined in two dimensional or three dimensional space.
• Vector graphics are sometimes used in computers because they can be scaled to a larger size without losing any image quality.