Question

Which of the following is a vector quantity?
1. Energy
2. Current
3. Displacement
4. Temperature

Answer 1

Correct Answer - Option 3 : Displacement

CONCEPT:

• All measurable quantities are divided into two broad categories:

Scalar quantities	Vector quantities
The physical quantities which have only magnitude and no direction are called scalar quantities or scalars.	The physical quantities which have both magnitude and direction and obey the laws of vector addition are called vector quantities or vectors.
A scalar quantity can be specified by a single number, along with the proper unit.	A vector quantity is specified by a number with a unit and its direction.
Examples: Mass, volume, density, time, temperature, electric current, distance, Energy, speed, etc.	Examples Displacement, velocity, force, weight, torque, momentum, acceleration, velocity, etc.

EXPLANATION:

• Energy is quantity has only magnitude. It does not require any direction. So it is a scalar, not vector quantity.
• Similarly, the current has only magnitude and does not require direction.
  • However while measuring current we give direction, but this direction is along the wire only. For vectors, we take direction in x, y, and z axes i.e. \(\widehat{i},\widehat{j}, and\space \widehat{k}\)
• Displacement is a vector quantity because while measuring displacement we have to consider direction also.
• The temperature has only magnitude. So a scalar quantity.
• So the correct answer is option 3.