📘 Relative Density: Conceptual & Numerical Questions
1. Define Relative Density.
Relative density = Density of substance / Density of water
2. What is the unit of Relative Density?
It has no unit (it is a ratio).
3. What is the relative density of water?
1
4. State one application of Relative Density in daily life.
Testing purity of gold or milk.
5. A body weighs 100 N in air and 80 N in water. Find its relative density.
Relative density = 100 / (100 - 80) = 5
6. The density of a substance is 5 g/cm³. What is its relative density?
Relative density = 5 / 1 = 5
7. Why do iron nails sink in water?
Because their relative density is greater than 1.
8. A material floats in water. What can you say about its relative density?
Its relative density is less than 1.
9. A body of volume 50 cm³ weighs 400 g in air and 300 g in water. Find its relative density.
Relative density = 400 / (400 - 300) = 4
10. State the principle used to find relative density of irregular solids.
Archimedes’ Principle
11. What happens when a body of relative density 0.8 is immersed in water?
It floats.
12. What is the relation between relative density and floatation?
If R.D. < 1 → floats; R.D. > 1 → sinks
