Physical Quantities and Measurement

Question 1

What is mass?

Answer 1

Mass is the matter contained in a substance.

Question 2

What is volume?

Answer 2

Volume is the amount of space occupied by a substance.

Question 3

What is density?

Answer 3

It is defined as the mass per unit volume of a substance

Question 4

How to find density? [ formula ]

Answer 4

Density=mass/volume

Question 5

CGS unit of density?

Answer 5

g/cm3

Question 6

SI unit of density?

Answer 6

kg/m3

Question 7

1000kg/m3=?

Answer 7

1g/cm3

Question 8

Density of water?

Answer 8

1g/cm3

Question 9

Mass of a solid can be measured using which device?

Answer 9

Beam balance

Question 10

How can you measure the volume of an irregular substance?

Answer 10

Volume of an irregular substance can be found by a method called displacement of liquids.

Question 11

Define displacement of liquids.

Answer 11

According to this method, when a solid is completely immersed into water , it displaces a certain amount of volume which is equal to its own volume.

Question 12

What all instruments can be used for the displacement of liquids?

Answer 12

Eureka can[overflow jar] and measuring cylinder

Question 13

How can you find the density of liquids?

Answer 13

By using a density bottle or by measuring the liquid’s mass with a beam balance and volume with a measuring cylinder

Question 14

Define density bottle.

Answer 14

It is a bottle specially designed to measure the density of liquids. Its capacity is 50ml.

Question 15

What is the specialty of a density bottle?

Answer 15

The specialty of the density bottle is that the same volume of liquid is obtained every time when the bottle is filled with different liquid.

Question 16

Define relative density.

Answer 16

Relative density[RD] is the ratio of the substance to the density of water at 4 degree Celsius.

Question 17

Relative density formula?

Answer 17

density of substance/density of water at 4 degree Celsius.

Question 18

Fact

Answer 18

Relative density has no unit.

Question 19

Compare the densities of solids, liquids and gases.

Answer 19

The density of solids is more than liquids. The density of liquids is more than gases.

Question 20

Fact

Answer 20

RD can also be found using a density bottle.

Question 21

Fact

Answer 21

Density of a substance can increase with decrease in temperature and decrease with increase in temperature

Question 22

What is meant by anomalous expansion of water?

Answer 22

The expansion of water when cooled from 4 degree to 0 degree.

Question 23

What is meant by convection current?

Answer 23

The circular movements or currents within a fluid due to different densities of hotter and cooler parts.

Question 24

Examples of convection current

Answer 24

Boiling of water, blowing of wind, see breeze and land breeze.

Question 25

Object sinks

Answer 25

density of an object is more than that of water

Question 26

Object floats

Answer 26

density of an object is lesser than that of water

Question 27

Object remains suspended

Answer 27

Same density as water

Question 28

Reference mark on the hull of the ship

Answer 28

Plimsol line

Question 29

Density of a huge mass of ice

Answer 29

iceberg

Question 30

Fact

Answer 30

Density of sea water is greater than the density of freshwater due to dissolved salts.