NCERT Solutions For Class 7 Science Chapter 4

NCERT Solutions Class 7 Science Heat

Ncert Solutions For Class 7 Science Chapter 4 PDF Free Download

NCERT solutions class 7 science chapter 4 heat is provided below to help students of class 7 understand the concepts of Heat in an interactive manner. The NCERT solutions for class 7 science chapter 4 heat is one of the most crucial chapters in class 7 science.

This chapter focuses on questions regarding heat and measurement of heat. We will be seeing questions on the difference between clinical and laboratory thermometer. We will analyze the difference between heat and temperature by solving various questions given in this chapter. We will be seeing questions on conductors and insulators and their examples. We have fill in the blanks questions where, you have to fill the appropriate words to make the sentences meaningful. This chapter consists of a special type of questions for easier understanding.

We have a match the following type questions which will enable you to match the correct answers to the right statements Have you wondered why wearing multiple layers of clothes in winter makes you stay warm ?, find out the answers why here. You will be given an image where you have to mark the places where conduction, convection and radiation happens.

Do you know why the buildings in hotter climate is painted white on the outside, want to know the answer to that question ?, find it out here. What will happen when you mix two liquids having different temperatures, what will happen to the temperature of the mixture ?, find it out here. You will be facing questions like these and practicing these will help you get an overall idea of this entire chapter.

Question 1:

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

Answer:

Similarities between the laboratory thermometer and the clinical thermometer

  1. Laboratory thermometer and the clinical thermometer thermometers consist of long narrow uniform glass tubes.
  2. Laboratory thermometer and the clinical thermometer have a bulb at one end.
  3. Laboratory thermometer and the clinical thermometer contain mercury in the bulb.
  4. Laboratory thermometer and the clinical thermometer use Celsius scale on the glass tube.

Differences between the laboratory thermometer and the clinical thermometer:

A clinical thermometer reads temperature 35°C to 45°C while the range of laboratory thermometer is -10°C to 110°C.

The clinical thermometer has a kink near the bulb while there is no kink in the laboratory thermometer. Due to kink, mercury does not fall down on its own in clinical thermometer.

 

Question2:

Give two examples each of insulators and conductors of heat.

Answer:

Conductors – silver, copper

Insulators – rubber, plastic.

 

Question3:

Complete the sentence with appropriate answers:

  1. ____________ can determine an object’s hotness.
  2. ___________ Thermometer cannot be used to measure the temperature present in boiling water.
  3. __________ Degree is used to measure temperature.
  4. ___________ requires no medium for heat transfer for the process.
  5. An ice-cold steel fork is dipped into a mug of hot water. The transfer of heat to the other end is by the process of ___________.
  6. ____________ Color clothes absorb heat better than clothes of light colors.

Answers:

  1. Temperature can determine the object hotness.
  2. Clinical Thermometer cannot be used to measure the temperature of boiling water.
  3. Celsius Degree is used to measure temperature.
  4. Radiation requires no medium for heat transfer for the process
  5. An ice-cold steel fork is dipped into a mug of hot water. Transfer of heat to the other end is by the process of conduction.
  6. Dark Color clothes absorb heat better than clothes of light colors.

 

Question 4:

Match the following:

1. Land breeze blows during (a) day
2. Sea breeze blows during (b) summer
3. Dark colored clothes are preferred during (c) night
4. Light colored clothes are preferred during                        (d) winter

Answers:

1. Land breeze blows during (c) night
2. Sea breeze blows during (a) day
3. Dark colored clothes are preferred during (d) winter
4. Light colored clothes are preferred during                        (b) summer

 

 

Question5:

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

Answer:

More layers of clothing actually keep us warmer in winters as they have a lot of space between them. That space gets filled up with air. Air is a bad conductor; it does not allow the body heat to escape out.

 

Question6:

Mark the places in which the heat is being transferred by convection, conduction and by radiation.

Answer:

5

 

Question7:

Explain why buildings in the places that have hotter climate are advised to paint the outer walls white.

Answer:

Since the white color reflects heat, it helps the house to not get heated up so much.

 

Question8:

When a liter of water at 50°C is mixed with another liter of water at 30°C what will be the temperature of the mixture?

(1)80°C                        (2) lesser than 80°C but greater than 50°C

(3) 20°C                       (4) Between 50°C and 30°C

Answer:

(4)Between 50°C and 30°C

 

Question9:
In a mug that contains water at 40°C, an iron ball which is 40°C is dropped. Mention the flow of heat:

  1. Flow from the iron ball to water.
  2. Will not flow from water to iron ball or from iron ball to water.
  3. Will flow from the water to the iron ball.
  4. Both the temperatures increase.

 Answer:

(2) Will not flow from water to iron ball or from iron ball to water.

 

Question10:

A wooden fork is dipped in a bowl of ice-cold water and its other end:

  1. Becomes cold due to the process of convection
  2. becomes cold due to the process of radiation
  3. becomes cold due to the process of conduction
  4. Doesn’t become cold.

Answer:

(4) Doesn’t become cold.

 

Question 11:

Why stainless steel pans that we use at home is are provided with copper bottoms? The reason might be:

  1. Such type of pans appear to be colorful
  2. Copper is a much better conductor of heat than that of stainless steel.
  3. Copper is much easier to clean after use when compared to that stainless steel
  4. Copper bottoms in pans are more durable.

Answer:

(2) Copper is a much better conductor of heat than that of stainless steel.

The NCERT solutions class 7 science chapter 4 pdf is prepared by expert science teachers according to the latest syllabus of the Central Board of Secondary Education. Check the NCERT solutions class 7 science chapter 4 given.


Practise This Question

Which gas is produced by the plants during the process of photosynthesis?