Hot water is poured simultaneously in four metallic tumblers painted outside with different points. After some time the water will be found to have cooled most in the tumbler painted.
A. Rough white
B. Rough black
C. Shining white
D. Shining black
Select an option to see the answer and solution.
Which of the following criterion is used for any metal to be used as a cooking material ?
A. More specific heat
B. More thermal conductivity
C. Less thermal conductivity
D. Less electrical conductivity
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Heat from the sun reaches earth by the process of
A. Conduction
B. Convection
C. Radiation
D. All of the above
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Ocean currents are an example of
A. Convection
B. Conduction
C. Insulation
D. Radiation
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What type of heat transfer is boiling water?
A. Radiation
B. Conduction
C. Convection
D. None of the above
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Ventilators are provided near the ceiling of the room because
A. The exhaled warmer air rises up and goes out
B. These provide cross ventilation in the room
C. These provide some sunlight in the room
D. These do not look nice in the lower part
Select an option to see the answer and solution.
Wollen clothes keep the body warm because
A. Wool increases the temperature of the body
B. Wool is a bad conductor
C. Wool absorbs radiant heat from outer objects
D. Wool rejects heat from the outer objects
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Plants are dried up in winter due to frost because
A. Evaporation does not take place
B. Photosynthesis does not take place at such low temperature
C. Respiration does not take place at low temperature
D. There is mechanical loss of tissues and drought condition prevails
Select an option to see the answer and solution.
A cup of hot coffee is placed on a metal table in a room. By which of the following methods does it lose heat?
A. Conduction and convection only
B. Conduction and radiation only
C. Convection and radiation only
D. Conduction, convection and radiation
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In general, which is the cause of a land breeze?
A. Pressure
B. Heat
C. Temperature
D. None of the above
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Heat from the Sun reaches the Earth by
A. Reflection
B. Conduction
C. Radiation
D. Convection
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Heat transfer by conduction occurs when molecules
A. Collide
B. Combine
C. Heated
D. None of the above
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A body absorbs heat most if it is
A. Black and rough
B. Black and smooth
C. White and rough
D. White and smooth
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A black body can absorb radiations of :
A. Lower wavelengths only
B. Intermediate wavelengths only
C. Higher wavelengths only
D. All wavelengths
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The cover of a solar cooker is made of glass because
A. It absorbs sun's rays
B. It reflects sun's rays
C. It retains the heat inside by the green house effect
D. It rediates heat better than metals
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The base of an electric iron is brightly polished mainly
A. To make it smooth and frictionless
B. To make it rust-proof
C. To reduce heat loss by radiation
D. To make it more durable
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A stone floor feels cold to the bare feet but a carpet on the same floor feels warm. This is because
A. The floor and carpet are at different temperatures
B. The stone conveys the heat away from the feet more rapidly than the carpet
C. The carpet is a better conductor of heat than the stone
D. The human body maintains a constant temperature
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Global warming is expected to result in
A. Increase in level of sea
B. Change in crop pattern
C. Change in coast line
D. All of the above
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Why two thin shirts can keep us warmer than a single thick shirt in winter ?
A. Two thin shirts become thicker so prevent transmission of heat
B. Air layer between two shirts works as good conductor
C. Air layer between two shirts behaves like insulating media
D. No radiation of heat takes place
Select an option to see the answer and solution.
Sun's heat reaches us by
A. Conduction
B. Convection
C. Radiation
D. Reflection
Select an option to see the answer and solution.
