Question

Which of the following physical quantities is a vector?

• A. Electric flux
• B. Electric potential
• C. Electric potential energy
• D. Electric intensity

Hint:

Remember that quantities named 'potential' or 'energy' in physics are almost always scalars. Quantities named 'field' or 'force' are vectors. 'Flux' is a scalar resulting from a vector field passing through a surface.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
A scalar quantity has only magnitude, while a vector quantity has both magnitude and direction. We need to identify which of the given electrical quantities is a vector.
Step 2: Detailed Explanation:
(A) Electric flux (\(\Phi_E\)): It is the measure of the flow of the electric field through a given area. It is defined by the dot product \(\Phi_E = \vec{E} \cdot \vec{A}\). The dot product of two vectors results in a scalar. So, electric flux is a scalar.
(B) Electric potential (V): It is the work done per unit charge to move a charge from a reference point to a specific point in an electric field. It is a scalar quantity, representing potential energy per unit charge.
(C) Electric potential energy (U): It is a form of energy and, like all forms of energy, it is a scalar quantity.
(D) Electric intensity: This is another term for the electric field strength (\(\vec{E}\)). The electric field at a point is defined as the force experienced by a unit positive charge placed at that point. Since force is a vector, the electric field is also a vector, having both magnitude and direction.
Step 3: Final Answer:
Among the given options, only electric intensity (electric field) is a vector quantity. Therefore, option (D) is correct.