Heat - Class 7 Physics - Extra Questions

At what temperature does water begin to expand when cooled ?



Name three bad conductors of heat.



Give reason : we wear a number of garments in winter rather than one thick garment 



Give reason : An iron chair feels colder than a wooden chair in winter 



Give reason as to why woolen clothes are more preferable in winter.



A cold steel spoon is dipped in a cup of hot milk. It transfer heat to its other end by the process of ___________.



Which of the following is the worst conductor of heat
(A) Asbestos         (B) Rubber
(B) Plastic             (C) Graphite



Fill in the blanks:                    
We use a _____________ for measuring the temperature of a body.



Name a liquid which is a good conductor of heat.



Poor conductors are known as ____. 



Name the instrument used to measure the temperature of a body.



A temperature is an objective comparative measure of how hot or cold a body is. Its S.I. unit is kelvin $$(K).$$ Type 1 for true and 0 for false.



Why are the mud houses provided with thatched roofs?



What is a Thermostat?



Name three good conductors of heat



Describe a Pyrometer.



Define Temperature of a body.



Describe the construction of a laboratory thermometer.



Why does a clinical thermometer have a kink?



Give reason as to why a newly made quilt is warmer than an old one.



Laboratory thermometers have a range of  $$-10^oC$$ to $$_______$$$$^\circ$$C 



State four reasons for using mercury as a thermometric liquid.



The degree of hotness and coldness of the body is called ____________.



The degree of hotness or coldness of a body is called __________ (heat/temperature).



Temperature is expressed in __________(degree centrigrade $$OR$$  joule).



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



Is ebonite handles would not permit heat to be conducted from hot utensil to hand?



The ............... of the body rises, when it is heated.



What is the use of kink in clinical thermometer?



Clothes of ________ (dark, white) colors absorb heat better than clothes of light colors.



Temperature of boiling water cannot be measured by a ________ (clinical, laboratory) thermometer.



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



A laboratory thermometer A is kept $$7\,cm$$ away,an the side of the flame while a similar thermometer.B is kept $$7\,cm$$ above the flame as shown in figure,which of the thermometer $$A$$ and $$B$$ , will show a greater rise in temperature.Give reason for your answer.



What is the difference in the temperatures and thermometers?



What is temperature?



To keep her soup warm Paheli wrapped the container in which it was kept with a woollen cloth Can she apply the same method to keep a glass of cold drink cool? Give reason for your answer.



At a camp site there are tents of two shades - one made with black fabric and the other with white fabric. Which one will you prefer for resting on a hot summer afternoon? Give reason for your choice. Would you like to prefer the same tent during winter?



Fill in the blanks:
The thermometer used to measure the human body temperature is called the .............. thermometer.



Is the bulb of a thermometer made of diathermic walls or adiabatic walls?



Shopkeepers selling ice blocks usually cover them with jute sacks. Explain why.



Why is it advised not to hold the thermometer by its bulb while reading it?



You may have noticed that a few sharp jerks are given to clinical thermometer before using it. Why is it done so?



Fill in the blanks:            
A person is said to have fever if his body temperature is more than _________.



What does the temperature measure ?



Fill in the blanks:                   
The temperature of a normal human body is _________.



Write the temperature of melting ice.



Write down the body temperature of a healthy person.



What is meant by the term temperature.



The S.I. unit of temperature is ____________.



Name the S.I. unit and one common unit of temperature. Write their symbols also.



Select a good and bad conductor of heat from the following:
copper, mercury, wood, iron, air, saw-dust, cardboard, silver, plastic, wool.



Name a liquid which is a good conductor of heat.



Why is an oven made of double walls with the space in between filled with cork?



Explain why we wear woolen clothes in winter.



What are the good and bad conductors of heat? Give two examples of each.



Name a solid which is a good conductor of heat.



In summer, ice is kept wrapped in a gunny bag. Explain the reason.



Explain why the water pipes are covered with cotton during very cold weather.



Why are quilts filled with fluffy cotton?



Why is tea kettle provided with an ebonite handle?



Write the names of two conductors and insulators.



Why do we prefer to wear white or light coloured clothes in summer and black or dark coloured clothes in winter?



Explain the conduction mode of heat transfer'



Define temperature and name its S.I. unit.



Why does a piece of ice when touched with hand, appear cool? Explain.



Temperature is measured in degree _______.



Give scientific reasons:
Before use, the clinical thermometer is jerked



Why is ice packed in sawdust? Explain.



Fill in the blanks
A cold steel spoon is dipped in a cup of hot milk. It transfers heat to its other end by the process of______



Fill in the blanks :
Temperature of boiling water cannot be measured by a ______ thermometer.



Define Conduction.



Draw a diagram of clinical thermometer.



Why is a person able to remove a piece of dry aluminum foil from a hot oven with bare fingers, whereas a burn results if there is moisture on the foil?



What are insulators ? Give example.



What are Conductors ? give example. 



The clinical thermometer is used to measure the temperature of _____ only.



It is the morning of a day that will become hot. You just purchased drinks for a picnic and are loading them,with ice, into a chest in the back of your car. (a) You wrap a wool blanket around the chest. Does doing so help to keep the beverages cool, or should you expect the wool blanket to warm them up? Explain your answer. (b) Your younger sister suggests you wrap her up in another wool blanket to keep her cool on the hot day like the ice chest. Explain your response to her.



Give reasons.
(a) After a hot sunny day, we sprinkle water on the roof or open ground.
(b) Perspiration keeps our body cold.
(c) Ice is rubbed on burnt part of the skin



What are the precautions to be taken while using a clinical thermometer.



Write the principle on which the thermometer is made.



What do you understand by the term temperature ? Distinguish between laboratory and clinical thermometers.



Mention the two special features of clinical thermometer.



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



Fill in the blanks:
The normal temperature of human body is .......$$^\circ C$$ or ......... $$^\circ F.$$



Draw a neat labelled diagram of a laboratory thermometer.



State the three units of temperature.



Write the construction of clinical thermometer.



What are the precautions should we take while using the clinical thermometer ?



How is the temperature read in the clinical thermometer?



Why are traditional clinical thermometers shook before checking temperature?



Why does the clinical thermometer has a range?



Class 7 Physics Extra Questions