Class 7 Science - Chapter Heat NCERT Solutions | Fill in the blanks : (a) The hotness of
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. It transfers heat to its other end by the process of ______________.
(f ) Clothes of ______________ colours absorb heat better than clothes of light colours.
(a) Temperature
Temperature: Temperature is a measure of how hot or cold something is, specifically, a measure of the average kinetic energy of the particles in an object, which is a type of energy associated with motion. Temperature is measured in degrees Celsius.
(b) Clinical thermometer
Clinical thermometer: A clinical thermometer cannot be used to measure high temperatures because it has been designed to measure only human body temperature which varies over a short range. If a clinical thermometer is used to measure high temperatures, it will get damaged.
(c) Celsius
Celsius: Celsius, also called centigrade, scale based on 0 0 Celsius for the freezing point of water and 100 0 for the boiling point of water.
(d) Radiation
It is the mode of transfer of heat in which heat is transferred through radiations. Example: sun etc.
(e) Conduction
Conduction: Those materials which allow heat to pass through them easily are called good conductors of heat. All the metals are good conductors of heat and electricity as well.
(f) Dark colour
Black colour absorbs all the wavelength of lights which are not reflected back to our eyes. it means black colour shirt or cloth absorbs all the light and convert this light into the form of energy (into the heat).
More Questions From Class 7 Science - Chapter Heat
- Q:-
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 - Q:-
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 - Q:-
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. - Q:-
Look at Fig. 4.13. Mark where the heat is being transferred by conduction, by convection and by radiation.
- Q:-
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. - Q:-
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. - Q:-
Discuss why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing.
- Q:-
In places of hot climate it is advised that the outer walls of houses be painted white. Explain.
- Q:-
Give two examples each of conductors and insulators of heat.
- Q:-
State similarities and differences between the laboratory thermometer and the clinical thermometer.
Popular Questions of Class 7 Science
- Q:-
State differences between acids and bases.
- Q:-
Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food - Q:-
Name the elements that determine the weather of a place.
- Q:-
Fill the missing word in the blank spaces in the following statements:
(a) Wind is——————air.
(b) Winds are generated due to —————— heating on the earth.
(c) Near the earth’s surface __________air rises up whereas ___________ air comes down.
(d) Air moves from a region of ——— pressure to a region of ———. - Q:-
In addition to the rock particles, the soil contains
(i) air and water
(ii) water and plants
(iii) minerals, organic matter, air and water
(iv) water, air and plants - Q:-
Why does an athlete breathe faster and deeper than usual after finishing the race?
- Q:-
Match structures given in Column I with functions given in Column II.
Column I Column II
(i) Stomata (a) Absorption of water
(ii) Xylem (b) Transpiration
(iii) Root hairs (c) Transport of food
(iv) Phloem (d) Transport of water
(e) Synthesis of carbohydrates - Q:-
Fill in the blanks:
(a) Production of new individuals from the vegetative part of parent is called_____________.
(b) A flower may have either male or female reproductive parts. Such a flower is called_____________.
(c) The transfer of pollen grains from the anther to the stigma of the same or of another flower of the same kind is known as _____________.
(d) The fusion of male and female gametes is termed as _____________.
(e) Seed dispersal takes place by means of _____________, _____________ and _____________. - Q:-
Classify the following as motion along a straight line, circular or oscillatory motion:
(i) Motion of your hands while running.
(ii) Motion of a horse pulling a cart on a straight road.
(iii) Motion of a child in a merry-go-round.
(iv) Motion of a child on a see-saw.
(v) Motion of the hammer of an electric bell.
(vi) Motion of a train on a straight bridge. - Q:-
Why do organisms need to take food?
Recently Viewed Questions of Class 7 Science
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Distinguish between a parasite and a saprotroph.
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The water holding capacity is the highest in
(i) sandy soil
(ii) clayey soil
(iii) loamy soil
(iv) mixture of sand and loam - Q:-
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Label Fig. 2.11 of the digestive system.
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Zubeda made an electric circuit using a cell holder shown in Fig. 14.4, a switch and a bulb. When she put the switch in the ‘ON’ position, the bulb did not glow. Help Zubeda in identifying the possible defects in the circuit.
- Q:-
Match the items in Column I with those in Column II:
Column I Column II
(a) Yeast (i) Earthworm
(b) Diaphragm (ii) Gills
(c) Skin (iii) Alcohol
(d) Leaves (iv) Chest cavity
(e) Fish (v) Stomata
(f) Frog (vi) Lungs and skin
(vii) Tracheae - Q:-
In addition to the rock particles, the soil contains
(i) air and water
(ii) water and plants
(iii) minerals, organic matter, air and water
(iv) water, air and plants
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