A student determines the density of a liquid and then compares it with the density of water to calculate its relative density. Which statement correctly distinguishes these two quantities?
Density has units, whereas relative density is a dimensionless quantity.
Density is mass per unit volume, \(\rho = \frac{m}{V}\), with SI unit kg/m³.
Relative density is the ratio \(\text{RD} = \frac{\rho_{\text{substance}}}{\rho_{\text{water}}}\). Since it divides one density by another, the units cancel and RD is a pure number (dimensionless).
So only density carries units; relative density has none.
Relative density is not always numerically greater: a liquid with ρ = 800 kg/m³ has RD = 0.8.
Dividing a substance's density by that of water gives relative density, not density.
Hence, the answer is Density has units, whereas relative density is a dimensionless quantity.
Similar Questions
A homogeneous material is altered so that its mass becomes three times its original value while its volume becomes twice its original value. What is the new density compared to the original density?
A body is moved to a planet where the acceleration due to gravity is reduced by 30% compared with Earth. Assuming its mass remains unchanged, which statement is correct?
A body weighs W1 at a place where the acceleration due to gravity is g1. At another place, its weight becomes 5/3 W1. Assuming the mass of the body remains constant, what is the ratio g2:g1?
A container holds a fixed mass of gas. The gas is compressed until its volume is reduced in the ratio 5 : 2. Compared to its initial value, the density of the gas becomes ______.
A solid metal block and a gas enclosed in a flexible balloon are subjected to the same increase in external pressure. Which one experiences the greater increase in density?
An astronaut carries a metal block from the Earth to the Moon. Which physical quantity of the block remains the same throughout the journey?
Important Questions from Mass Weight and Density
The body will move only when
Mass and weight ________
- What is the formula for density?
A spherical aluminium ball is melted and made into smaller balls of the 1/3rd radius of original one. Then how many such balls can be made?
The weight of 75 m3 volume of metal is 150 gm. Find the weight of 300 m3 volume of same metal
