Viva Voce: Density of Solid | Lab Manuals for Class 9 PDF Download

Q.1. State the S.I. unit of density.

kg/m³

Q.2. Define density.

Density is defined as the mass per unit volume.

Q.3. How can you convert the weight value into mass?

The weight of a body = mass x g, to get mass, divide the given weight by g.

Q.4. A measuring cylinder has 5 marks between 10 mL to 20 mL. What is its least count?

20 mL – 10 mL =10 mL, Let ‘x; is the least count.

5 * x= 10

x = 10/5 = 2
Each mark is of 2 mL value.

Q.5. A rectangular body has dimensions x and y (/ and b). If its dimensions get doubled what will happen to its volume?

Suppose the dimensions of a rectangular solid is 1 then
V = 1 x 1 x 1 (l x b x h taken as 1)
V= l³
If it is doubled, then V = 2>
V = 8 times
hence volume will increase by 8 times.

Q.6. State two precautions while measuring the volume in the cylinder.

(i) The measuring cylinder should be placed on a plain flat surface.
(ii) The lower meniscus and eye line should be parallel.

Q.7. The density of water is 1 kg/m³ at 4^° C. What will happen to its density if the temperature falls?

With the decrease in the temperature, the density of water decreases.

Q.8. If you are given a choice to choose a spring balance with different least count values to do the experiment. Which one will you choose?

I  will choose the spring balance which has the minimum value of least count to get accurate readings.

Q.9. What precautions will you take while holding the spring balance to find the weight of a body?

The spring balance should be held only at the hook on the top end, never hold the spring balance from its sides.

Q.10. At what temperature the density of water is maximum?

At 4^°C

Q.11. A spring balance has a zero error of 2 divisions and there are 10 marks between 0-10 N. Find the value of zero error.

0-10 N has 10 divisions hence each division mark indicates 1 N. Hence, the zero error is 2 N.

Q.12. What is the principle of spring balance?

The spring gets stretched due to the force exerted on it, this stretching produced is directly proportional to the stretching force.

Q.13. The density of a solid is 2.5 g/cm³. What does it mean?

It means that 2.5 g of solid has a volume of 1 cm³

Q.14. How can you measure 1 N weight?

It can be measured by using spring balance.

Q.15. How do you find mass and weight of the body?

To find mass I will use a beam balance and to find weight I will use a spring balance.