Question

PHYSICS

CHAPTER 2

A. Objective Questions

1. Write true or false for each statement

(a) Equal volumes of the two different substances have equal masses.

(b) The density of a piece of brass will change by changing its size or shape.

(c) The density of a liquid decreases with increase in its temperature.

(d) Relative density of water is 1.0.

(e) Relative density of a substance is expressed in gm-3.

(f) When a body is immersed in a liquid, the buoyant force experienced by the body is equal to the volume of the liquid displaced by it.

(g) A body experiences the same buoyant force while floating in water or alcohol. A body experiences the same buoyant force when it floats or sinks in water.

(h) A body floats in a liquid when its weight becomes equal to the weight of the liquid displaced by its submerged part

(i) ) A body while floating, sinks deeper in a liquid of low density than in a liquid of high density.

2. Fill in the blanks

(a) 1kg is the mass of______ water at 4°C.

(b) Mass = density × ______

(c) The S.I. unit of density is _____

(d) Density of water is ______

(e) 1 g cm-3 = ______

(f) The density of a body which sinks in water is ____than 1000 Kg

(g) A body sinks in a liquid A; but floats in a liquid. The density of liquid is ____than the density of liquid B

(h) A body sinks in water, but a body Y floats on water. The density of the body is ____ than the density of the body.

(i) The buoyant force experienced by a body when floating in salt-water is ______ to or same that of when floating in pure water.

(j) The weight of a body floating in a liquid is _____

3. . Select the correct alternative

(a) The correct relation is

1. Density = Mass × Volume

2. Mass = Density × Volume

3. Volume = Density × Mass

4. Density = Mass + Volume

(b) The relative density of alcohol is 0.8 its density is

1. 0.8

2. 800 kg 3

3. 800 g 3

4. 0.8 kg −3

(c) A block of wood of density 0.8gcm-3 has a volume of 60cm3 . The mass of block is

1. 1. 60.8 g

2. 75 g

3. 48 g

4. 0.013 g

(d) The density of aluminium is 2.7 g3 and that of brass 8.4 3 . The correct statement is

1. Equal masses of aluminium and brass have equal volumes

2. The mass of a certain volume of brass is more than the mass of equal volume of aluminium.

3. The volume of a certain mass of brass is more than the volume of equal mass of aluminium.

4. Equal volumes of aluminium and brass have equal masses.

(e) A density bottle has a marking 25 mL on it. It means that:

1. the mass of density bottle is 25g

2. the density bottle will store 25 ml of any liquid in it

3. the density bottle will store 25 ml of water, but more volume of liquid denser than water.

4. the density bottle will store 25 ml of water, but more volume of a liquid lighter than water.

(f) The correct statement is

1. The buoyant force on a body is equal to the volume of the liquid displaced by it

2. The buoyant force on a body is equal to the volume of the body

3. The buoyant force on a body is equal to the weight of the liquid displaced by it

4. The buoyant force on a body is always equal to the weight of the body.

(g) A piece of wood floats on water. The buoyant force on wood will be

1. zero

2. more than the weight of the wood piece

3. equal to the weight of the wood piece

4. less than the weight of the wood piece.

(h) The weight of a body is more than the buoyant force experienced by it, due to a liquid. The body will 1. Sink

2. float with its some part outside the liquid

3. float just below the surface of liquid

4. Float with whole of its volume above the surface of liquid.​

Answer 1

Explanation:

true

true

false

false

true

false