VANASTHALI PUBLIC SCHOOL
SESSION:2021-22
SUBJECT:SCIENCE
GRADE: VII
CHAPTER 4 : HEAT
PRACTICE WORKSHEET
A.
Fill in the blanks: (1 Mark Each)
1. Thermal energy flows between objects due to difference in___________
2. When a liquid is heated it___________
3. Convection current gives rise to ___________
4. Dark colors are good___________ of heat.
5. The degree of hotness or coldness in a substance is called ___________
6.___________ is a conductor of heat.
7. The thermos flask is made up of double walled glass vessels because glass is a
___________
8. In solids transfer of heat can take place by ___________
9. Mercury is a liquid metal in ___________
10. The form of energy that flows from hot object to a cold object is called ___
11. The boiling point of water in the Celsius scale is ___________
12. The transfer of energy between object that are in physical contact is by __
13. The ___________ in a clinical thermometer prevents backflow of the Mercury
into the bulb.
14. The handle of cooking utensils are made of material that are___________
15. The vacuum in a thermos flask reduces the heat loss due to___________
B.
Multiple Choice Questions: (1 Mark each)
Q 1. A marble tile would feel cold as compared to a wooden tile on a winter
morning, because the marble tile
(a) is a better conductor of heat than the wooden tile.
(b) is polished while wooden tile is not polished.
(c) reflects more heat than wooden tile.
(d) is a poor conductor of heat than the wooden tile
Q 2. X and Y measured their body temperature. X found it to be 98.6 °F and
Y recorded 37 °C. Which of the following statement is true?
(a) X has a higher body temperature than Y.
(b) X has a lower body temperature than Y.
(c) Both have normal body temperature.
(d) Both are suffering from fever.
Q 3. Identify which one are poor conductors of heat?
(a) Water
(b) Copper
(c) Air
(d) Plastic
(e) Wood
(f) Iron
(g) Aluminium
C.
Short Answer type Questions: (1 Mark Each)
Q 1. Name two good conductors of heat?
Q 2. What is the lowest point of an ordinary laboratory thermometer?
Q 3. Why is the bulb of the thermometer made of thin glass?
Q 4. How does the fur of the polar bear help it to live in the Arctic region?
Q 5. Why does cold water kept in an open container become warm on a hot
summer afternoon?
Q 6 Answer the following in one word each:
(a) The SI unit of heat(b) The SI unit of Temperature(c) The instrument used to measure the temperature(d) The transfer of heat from hotter part to a colder part of an object due to
vibration of a particles(e) The material that do not conduct heatQ 7 Convert the given temperature to degree Celsius.
(a) 150 degree F
(b) 48 degree F
Q 8 Convert the given temperature to degree fahrenheit.
(a) 150 degree C
(b) 32 degree C
Q 9 Why is mercury used in thermometers?
Q 10 Give reason why :(a) Rooms are provided with ventilators & exhaust fans near top of side walls.
(b) It is advisable to place room heaters at the ground level for effective heating.
(c) Air conditioners should be installed at the top windows.
Q 11 Shopkeepers selling ice blocks usually cover them with jute sacks. Explain
Q 12 Why is the box of solar cooker painted black from inside?
Q.13 What is the relation between the Celsius scale and the fahrenheit scale?
Q 14.How do woolen garments keep us warm?
D. Value Based Questions: (3 Marks Each)
Q 1.Sarika likes to have curd in her lunch. She even knows that for setting curd, a
small amount of curd is added to warm milk. The microbes present in the curd help
in setting the curd, if the temperature of the mixture remains approximately
between 35°C to 40°C. But she is worried because it is winter and the room
temperature remains much below the range which makes setting of curd difficult.
(a) Suggest a way to Sarika to set curd in such a situation.
(b) Why setting of curd during winter season become difficult?
(c) Is eating curd good for health?
Q 2. Ramjas lived in an old house. His father thought of reconstructing the house.
He brought a new house plan design to home to show it to every family member.
Ramjas pointed out that the house lack ventilators and he is unhappy for that.
(a) Are ventilators important? Why?
(b) In summer, which color will you choose to paint outer wall of your house?
(c) What will happen if they use a black color to paint walls?