11. 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.
Stainless steel pans are usually provided with copper bottoms. The reason for this could be that
(c) copper is a better conductor of heat than the stainless steel.
10. 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.
Does not become cold
View Full Answer(4)9. 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.
If an iron ball at is dropped in a mug containing water at . Then, the heat will
(b) not flow from iron ball to water or from water to iron ball.
Because heat will flow from an object with high temperature to an object having a low temperature. But here temperature of both liquid and iron ball is same.
Therefore, no flow of heat take place
8. 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
If one litre of water at is mixed with one litre of water at . Then, the temperature of the mixture will be
(d) between and
Because as the volume of both the liquids with temperature and is equal. Therefore, when we add both the liquids there is transferred of heat take place from a liquid with high temperature to a liquid with a low temperature. That's why temperature is between and
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7. In places of hot climate it is advised that the outer walls of houses be painted white. Explain.
In places of hot climate it is advised that the outer walls of houses be painted white because white is a light colour and because of that it reflects back most of the heat that falls on it and a very less amount of heat is absorbed by the walls.
Therefore, a light colour tends to keep the house cool
View Full Answer(2)Look at Fig. 4.13. Mark where the heat is being transferred by conduction, by convection and by radiation.
Three stages are :-
i) Transfer of heat from burner to pan is take place through radiation.
ii) Transfer of heat from pan to water is take place through conduction.
iii) Transfer of heat within water is take place through convection.
5. Why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing.
we wear more thin layers of clothing instead of 1 thick layer as many layers trap air inside them. we know air is a bad conductor so it prevent heat loss
View Full Answer(3)
4. 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
These are the correct match
i) Land breeze blows durin (d) night
ii) Sea breeze blows during (c) day
iii) Dark coloured clothes are preferred during (b) winter
iv) Light coloured clothes are preferred during (a) summer
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. Heat is transferred to its other end by the process of ______________.
(f ) Clothes of ______________ colours absorb more heat better than clothes of light colours.
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 colours absorb more heat better than clothes of light colours.
2. Give two examples each of conductors and insulators of heat.
Two examples of
i) Conductor :-
1) Copper
2) Aluminium
ii) insulator :-
1) Plastic
2) Wood
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Stainless steel pans are usually provided with copper bottoms. The reason for this could be that
A wooden spoon is dipped in a cup of ice cream.Its other end
An iron ball at 40°C is dropped in a mug containing water at 40°C. The heat will
In places of hot climate it is advised that the outer walls of houses be painted white.
Match the following:(i) Land breeze blows during
Fill in the blanks: (a) The hotness of an object is determined by its______.
Give two examples each of conductors and insulators of heat.