Short type questions,Class 8 , ch 2 -Physical quantities Measurement

Short Answer Questions

Click each button to reveal the answer. Use the controls for quick revision.

Answers opened: 0 / 11

Q1 Define density of a substance.

Density is the mass of a substance per unit volume.
Density = Mass / Volume

Q2 Name the SI unit of density and convert it to g cm⁻³.

SI unit = kg m⁻³
1 kg m⁻³ = 0.001 g cm⁻³

Q3 What does density of brass = 8.4 g cm⁻³ mean?

It means 1 cm³ of brass has a mass of 8.4 g.

Q4 Arrange the following in increasing order of density: Iron, Cork, Brass, Water, Mercury.

Cork < Water < Iron < Brass < Mercury

Q5 How does the density of a liquid vary with temperature?

Density decreases with increase in temperature.

Q6 Which quantity changes when a liquid is heated: mass, volume or density?

Volume and density change. Mass remains constant.

Q7 Define relative density.

Relative density is the ratio of density of a substance to the density of water at 4°C.

Q8 What is the unit of relative density?

Relative density has no unit. It is dimensionless.

Q9 Explain the statement: relative density of aluminium is 2.7.

It means aluminium is 2.7 times denser than water.

Q10 State the law of floatation.

A floating body displaces a liquid equal to its own weight.

Q11 How is weight related to buoyant force for a floating body?

For a floating body, weight = buoyant force.