Consider the following pairs:
1. Scalar quantity – Energy
2. Vector quantity – Length
3. Scalar quantity – Pressure
How many of the above pairs are correctly matched?

Correct option is B

The Correct answer is(b) Only two pairs
Explanation:
• Pair 1 (Scalar quantity: Energy) is correct. Energy has magnitude only and is a scalar quantity.
• Pair 2 (Vector quantity: Length) is incorrect. Length is a scalar quantity. Displacement is the corresponding vector quantity.
• Pair 3 (Scalar quantity: Pressure) is correct. Pressure acts equally in all directions at a point and is a scalar quantity.
• Therefore, two pairs are correctly matched.
Information Booster:
• A scalar quantity is completely described by its magnitude only (examples: mass, time, distance, volume, temperature).
• A vector quantity is completely described by both magnitude and direction (examples: force, velocity, acceleration, momentum).
• Understanding the difference between scalar and vector quantities is fundamental in physics.
Additional Knowledge:
Length (in Pair 2)
• Length is a fundamental physical quantity measured in units like meters.
• While length describes size, it does not include direction.
Pressure (in Pair 3)
• Pressure is defined as force per unit area (P = F/A).
• Although force is a vector, pressure itself is a scalar because in a static fluid, it pushes equally in all directions at any given point.