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Fill in the blanks : (a) The hotness of an object is determined by it...

Fill in the blanks : (a) The hotness of | Class 7 Science Chapter Heat, Heat NCERT Solutions

Welcome to the NCERT Solutions for Class 7 Science - Chapter Heat. This page offers a step-by-step solution to the specific question from Exercise 1, Question 3: . With detailed answers and explanations for each chapter, students can strengthen their understanding and prepare confidently for exams. Ideal for CBSE and other board students, this resource will simplify your study experience.

Question 3:

Fill in the blanks :
(a) The hotness of an object is determined by its __________.
(b) Temperature of boiling water cannot be measured by a _____________ thermometer.
(c) Temperature is measured in degree ______________.

(d) No medium is required for transfer of heat by the process of __________.
(e) A cold steel spoon is dipped in a cup of hot milk. It transfers heat to its other end by the process of ______________.
(f ) Clothes of ______________ colours absorb heat better than clothes of light colours.

Answer:

(a) Temperature
Temperature: Temperature is a measure of how hot or cold something is, specifically, a measure of the average kinetic energy of the particles in an object, which is a type of energy associated with motion. Temperature is measured in degrees Celsius.

(b) Clinical thermometer
Clinical thermometer: A clinical thermometer cannot be used to measure high temperatures because it has been designed to measure only human body temperature which varies over a short range. If a clinical thermometer is used to measure high temperatures, it will get damaged.

(c) Celsius
Celsius: Celsius, also called centigrade, scale based on 0 0 Celsius for the freezing point of water and 100 0 for the boiling point of water.

(d) Radiation
It is the mode of transfer of heat in which heat is transferred through radiations. Example: sun etc.

(e) Conduction
Conduction: Those materials which allow heat to pass through them easily are called good conductors of heat. All the metals are good conductors of heat and electricity as well.

(f) Dark colour

Black colour absorbs all the wavelength of lights which are not reflected back to our eyes. it means black colour shirt or cloth absorbs all the light and convert this light into the form of energy (into the heat).

Other Questions of Chapter Heat

An iron ball at 40°C is dropped in a mug containing water at 40°C. The heat will

(a) flow from iron ball to water.
(b) not flow from iron ball to water or from water to iron ball.
(c) flow from water to iron ball.
(d) increase the temperature of both.

One litre of water at 30°C is mixed with one litre of water at 50°C. The temperature of the mixture will be

(a) 80°C (b) more than 50°C but less than 80°C
(c) 20°C (d) between 30°C and 50°C

Look at Fig. 4.13. Mark where the heat is being transferred by conduction, by convection and by radiation.

State similarities and differences between the laboratory thermometer and the clinical thermometer.

A wooden spoon is dipped in a cup of ice cream. Its other end

(a) becomes cold by the process of conduction.
(b) becomes cold by the process of convection.
(c) becomes cold by the process of radiation.
(d) does not become cold.

Stainless steel pans are usually provided with copper bottoms. The reason for this could be that

(a) copper bottom makes the pan more durable.
(b) such pans appear colourful.
(c) copper is a better conductor of heat than the stainless steel.
(d) copper is easier to clean than the stainless steel.

In places of hot climate it is advised that the outer walls of houses be painted white. Explain.

Match the following :
(i) Land breeze blows during (a) summer
(ii) Sea breeze blows during (b) winter
(iii) Dark coloured clothes are preferred during (c) day
(iv) Light coloured clothes are preferred during (d) night

Give two examples each of conductors and insulators of heat.

Discuss why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing.

Popular questions of class 7 Science

Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food

Here is a crossword puzzle: Good luck!

Across
3. Liquid waste products
4. Solid waste extracted in sewage treatment
6. A word related to hygiene
8. Waste matter discharged from human body

Down
1. Used water
2. A pipe carrying sewage
5. Micro-organisms which causes cholera
7. A chemical to disinfect water

Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.
Down Across
(D) 1 : Thorough washing (A) 1 : Keeps warm
2 : Animal fibre 2 : Its leaves are eaten by silkworms
3 : Long thread like structure 3 : Hatches from egg of moth

Sketch the cross section of soil and label the various layers.

Solve the following crossword puzzle with the clues given:

Across
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.

Down
1. In desert soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil.

Take three test-tubes. Fill æth of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO₂?

Sketch the reproductive parts of a flower.

Describe how crystals of copper sulphate are prepared.

Why does an athlete breathe faster and deeper than usual after finishing the race?

Write one similarity and one difference between the nutrition in amoeba and human beings.

Recently Viewed Questions of Class 7 Science

What are the components of blood?

Name the source from which litmus solution is obtained. What is the use of this solution?

Classify the following as motion along a straight line, circular or oscillatory motion:

(i) Motion of your hands while running.
(ii) Motion of a horse pulling a cart on a straight road.
(iii) Motion of a child in a merry-go-round.
(iv) Motion of a child on a see-saw.
(v) Motion of the hammer of an electric bell.
(vi) Motion of a train on a straight bridge.

Match the items given in Column I with those in Column II:
Column I Column II
Chlorophyll Bacteria
Nitrogen Heterotrophs
Amarbel Pitcher plant
Animals Leaf
Insects Parasite

How do elephant living in the tropical rainforest adapt itself?

Out of the following, which are the two terms related to silk production? Sericulture, floriculture, moriculture, apiculture and silviculture.

Hints:
(i) Silk production involves cultivation of mulberry leaves and rearing silkworms.
(ii) Scientific name of mulberry is Morus alba.

A simple pendulum takes 32 s to complete 20 oscillations. What is the time period of the pendulum?

Describe how crystals of copper sulphate are prepared.

The gas we use in the kitchen is called liquified petroleum gas (LPG). In the cylinder it exist as a liquid. When it comes out from the cylinder it
becomes a gas (Change – A) then it burns (Change – B). The following statements pertain to these changes. Choose the correct one.

(i) Process – A is a chemical change.
(ii) Process – B is a chemical change.
(iii) Both processes A and B are chemical changes.
(iv) None of these processes is a chemical change.

Can we survive only on raw, leafy vegetables/grass? Discuss.

Study Tips for Answering NCERT Questions:

NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:

Read the question carefully and focus on the core concept being asked.
Reference examples and data from the chapter when answering questions about Heat.
Review previous year question papers to get an idea of how such questions may be framed in exams.
Practice answering questions within the time limit to improve your speed and accuracy.
Discuss your answers with your teachers or peers to get feedback and improve your understanding.

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