# Measurement of Density and Speed Class-7th Goyal Brothers Physics Solutions

Measurement of Density and Speed Class-7th Goyal Brothers Physics Solutions Chapter-1. We Provide Step by Step Answers of Objective, True False , Fill in the blanks, Match the following , Study questions of Chapter-1,Physical Quantities and Measurement unit -2(Measurement of Density and Speed ) Visit official Website  for detail information about ICSE Board Class-7.

## Measurement of Density and Speed Class-7th Goyal Brothers

Physics Solutions Ch-1 (unit-3)

 Board ICSE Class 7th Subject Physics Book Name Goyal Brothers Theme-1 Physical Quantities and Measurement Unit-3 Measurement of Density and Speed Topic Solution of exercise questions Session 2023-24

### OBJECTIVE TYPE QUESTIONS

(Goyal Brothers Physics Solutions)

#### A. Fill in the blanks :

1. The density of iron is 7.8 gcm-3. The volume of 390 g of iron is _50_ cm3.
2. The density of _solid_ hardly changes with a rise in temperature by 20 degree celcius.
3. In SI system, unit of density is _Kgm-3_.
4. The density of water is 1 gcm-3. Therefore, 1 cm3 of water has a _mass_ of 1 g.
5. The distance covered by a body in unit time is called _speed_.

#### B. Statement given below are incorrect. write the correct correct statement:

1. Force per unit area of a substance is called density.

Correct Statement: Mass per unit area of a substance is called density.

2. The mass of a solid is determined by a spring balance very accurately.

Correct Statement: The mass of a solid is determined by a beam balance very accurately.

3. In SI system, unit of speed is Kmh-1.

Correct Statement: In SI system, unit of speed is ms-1.

4. In case of uniform speed, one can need to find the average speed of the body.

Correct Statement: In case of non-uniform speed, one can need to find the average speed of the body.

5. With the rise in temperature of air its density increases.

Correct Statement: With the rise in temperature of air its density decreases.

#### B. Write ‘True’ or ‘False’ for the following statements :

1. The mass per unit volume of a substance is called its density. [T]
2. A specially designed bottle is used for finding density of solids. [T]
3. All forms of matter expand on heating and contract on cooling. [T]
4. The speed can be found by dividing the distance covered by the time. [T]
5. If the distance covered are fairly large the speed is expressed in cm/s. [F]

#### 1. The density of gold is 19.6 gcm-3 in CGS system. Its density in SI system is :

(a) 196 kgm-3

(b) 1960 Kgm-3

(c) 19600 kgm-3

(d) no change in density

Ans: (c) 19600 kgm-3

#### 2.When a liquid is heated, it expands comparatively :

(a) more than solid

(b) less than gas

(c) less than solid

(d) either (a) or (b)

Ans: (d) either (a) or (b)

#### 3. In order to find the density of solid we have to know its :

(a) mass and area

(b) weight and volume

(c) weight and area

(d) mass and volume

Ans: (d) mass and volume

#### 4. When the air cools, its density :

(a) increases

(b) decreases

(c) does not change

(d) none of these

Ans: (a) increases

#### 5. In order to find speed of a moving body, we have to know its :

(a) displacement and time

(b) distance and time

(c) mass and volume

(d) distance and direction

Ans: (b) distance and time

#### Column B

1. A small glass bottle used for finding the density of a liquid. 1. ms-1
2. Mass per unit volume. 2. 1000 kgm-3
3. Distance per unit time. 3. Density
4. The unit of speed in SI system. 4. Density bottle
5. The density of fresh water in SI system. 5. Speed