NCERT Class 7 Science Chapter 4 - Heat

Chapter 4 - Heat

Question and Answers
Question 1: State similarities and differences between the laboratory thermometer and the clinical thermometer.
Answer:

Similarities
*Both are made of glass and consist of long narrow glass tube.
*At one end both of them have a bulb.
*Bulbs of both the thermometers consist of mercury
*Celsius scale is present in both the thermometer
Differences
Clinical Thermometer
*Temperature range is 35 to 42 Degree Celsius
* Used to measure human body temperature
* It has kink which prevents immediate back flow of mercury
Laboratory Thermometer
* Temperature range is -10 to 110 Degree Celsius
* Used to measure temperature in the laboratory
* It does not have a kink
 
Question 2: Give two examples each of conductors and insulators of heat.
Answer:

Conductors: Iron and Copper
Insulators: Plastic and wood
 
Question 3: Fill in the blanks :
(a) The hotness of an object is determined by its
temperature.
(b) Temperature of boiling water cannot be measured by a
clinical thermometer.
(c) Temperature is measured in Degree
Celsius.
(d) No medium is required for transfer of heat by the process of
radiation.
(e) A cold steel spoon is dipped in a cup of hot milk. Heat is transferred to its other end by the process of
conduction.
(f) Clothes of
dark colors absorb more heat better than clothes of light colors.

Question 4: Discuss why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing.
Answer:
More layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing because air gets trapped in-between layer. As air is a bad conductor of heat it does not allow the escape of the heat from the body.
 
Question 5: In places of hot climate it is advised that the outer walls of houses be painted white. Explain.
Answer:
In places of hot climate, it is advised that the outer walls of houses be painted white because white color reflects back most of the heat that is incident on it as white is a poor absorber of heat. This helps in keeping the house cool.
 
Question 6: 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
Answer:
(d) between 30°C and 50°C
 
Question 7: 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.
Answer:
(b) Not flow from iron ball to water or from water to iron ball.

Question 8: 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.
Answer:
(d) Does not become cold.
 
Question 9: 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 colorful.
(c) Copper is a better conductor of heat than stainless steel.
(d) Copper is easier to clean than stainless steel.
Answer:
(c) Copper is a better conductor of heat than stainless steel.

No comments:

Post a Comment

Also read!

Class 6 Solutions

• Class 7

Class 7 Computer Kips Solutions
Class 7 Gul Mohar English Solutions
English Grammar Class 7
English Writing Skills Class 7
Class 7 Map Pointing Solutions
Class 7 NCERT Civics Solutions
Class 7 NCERT Civics Notes
Class 7 NCERT Civics Extra Questions
Class 7 NCERT Geography Solutions
Class 7 NCERT Geography Notes
Class 7 NCERT Geography Extra Questions
Class 7 NCERT History Solutions
Class 7 NCERT History Notes
Class 7 NCERT History Extra Questions
Class 7 NCERT Maths Solutions
Class 7 NCERT Science Solutions
Class 7 NCERT Science Notes
Class 7 NCERT Science Extra Questions

• Class 8

Class 8 Kips Artificial Intelligence Solutions
Class 8 Gul Mohar English Solutions
English Grammar Class 8
English Writing Skills Class 8
Class 8 Map Pointing Solutions
Class 8 NCERT Civics Solutions
Class 8 NCERT Civics Notes
Class 8 NCERT Civics Extra Questions
Class 8 NCERT Geography Solutions
Class 8 NCERT Geography Notes
Class 8 NCERT Geography Extra Questions
Class 8 NCERT History Solutions
Class 8 NCERT History Notes
Class 8 NCERT History Extra Questions
Class 8 NCERT Maths Solutions
Class 8 NCERT Science Solutions
Class 8 NCERT Science Notes
Class 8 NCERT Science Extra Questions
Class 8 NCERT Science Exemplar
Class 8 NCERT Science MCQs

Class 9 Solutions

• Class 10

Class 10 Kips Artificial Intelligence Solutions
Class 10 NCERT English Solutions
→ Class 10 Map Pointing Solutions
Class 10 NCERT Civics Solutions
Class 10 NCERT Civics Notes
Class 10 NCERT Civics Extra Questions
Class 10 NCERT Geography Solutions
Class 10 NCERT Geography Notes
Class 10 NCERT Geography Extra Questions
Class 10 NCERT History Solutions
→ Class 10 NCERT History Notes
Class 10 NCERT History Extra Questions
Class 10 NCERT Maths Solutions
Class 10 NCERT Science Solutions
Class 10 NCERT Science Notes
Class 10 NCERT Science Extra Questions

• Computer languages
Python Basics

• Extra Activities
Extra Activities

• Extra Knowledge
Extra Information
General Knowledge
Historical Places in India
Latest technology
Physical Sciences
Facts

• Mathematics quick links
Mathematical Terms
Maths Tricks

CONTACT US