Physics miscellaneous
- The cooling by a desert Cooler is based on:
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Nature’s most efficient means of cooling is through the evaporation of water. Desert coolers make use of evaporative cooling that works on the principle of heat absorption by moisture evaporation. As water is evaporated, energy is lost from the air, reducing the temperature. Thus, cooling effect is produced.
Correct Option: C
Nature’s most efficient means of cooling is through the evaporation of water. Desert coolers make use of evaporative cooling that works on the principle of heat absorption by moisture evaporation. As water is evaporated, energy is lost from the air, reducing the temperature. Thus, cooling effect is produced.
- Which Article of the Indian Constitution provides free and compulsory education to children?
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According to Article 21A of Indian Constitution, theState shall provide free and compulsory education to all children of the age of six to fourteen years in such manner as the State may, by law, determine. This article was inserted in the constitution by 86th Amendment Act, 2002, also known as Right of Children to Free and Compulsory Education Act.
Correct Option: A
According to Article 21A of Indian Constitution, theState shall provide free and compulsory education to all children of the age of six to fourteen years in such manner as the State may, by law, determine. This article was inserted in the constitution by 86th Amendment Act, 2002, also known as Right of Children to Free and Compulsory Education Act.
- The magnitude of current flowing between two end points of a conductor is proportional to the potential difference between them and is called as:
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According to Ohm’s Law, the potential difference (V) between two terminals of a current-carrying conductor is directly proportional to the current (I), flowing through it. The proportionality constant R, is the resistance of the conductor. Thus, V α I
or V = I × Ror I = V or R = V R I
Correct Option: C
According to Ohm’s Law, the potential difference (V) between two terminals of a current-carrying conductor is directly proportional to the current (I), flowing through it. The proportionality constant R, is the resistance of the conductor. Thus, V α I
or V = I × Ror I = V or R = V R I
- Which one of the following reflects back more sunlight as compared to other three?
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Albedo is the fraction of solar energy (shortwave radiation) reflected from the Earth back into space. It is a measure of the reflectivity of the earth’s surface. Ice, especially with snow on top of it on land, has the highest albedo. The albedo of given sources is as follows:
• Fresh snow or ice: 60-90% or 80-95%;
• Desert sand: 30-50%;
• Prairie Grasslands: 18-25% or 20%;
• Crops: = 10-25%Correct Option: B
Albedo is the fraction of solar energy (shortwave radiation) reflected from the Earth back into space. It is a measure of the reflectivity of the earth’s surface. Ice, especially with snow on top of it on land, has the highest albedo. The albedo of given sources is as follows:
• Fresh snow or ice: 60-90% or 80-95%;
• Desert sand: 30-50%;
• Prairie Grasslands: 18-25% or 20%;
• Crops: = 10-25%
- Hydroscope is an instrument that shows changes in:
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Hydroscope is an optical device for enabling a person to see an object at a considerable distance below the surface of water by means of a series of mirrors enclosed in a steel tube. Hydrophone is an instrument used for recording sound under water. It is the underwater equivalent of a microphone that measures pressure fluctuations, and these are usually converted to sound pressure level (SPL), a logarithmic measure of the mean square acoustic pressure.
Correct Option: E
Hydroscope is an optical device for enabling a person to see an object at a considerable distance below the surface of water by means of a series of mirrors enclosed in a steel tube. Hydrophone is an instrument used for recording sound under water. It is the underwater equivalent of a microphone that measures pressure fluctuations, and these are usually converted to sound pressure level (SPL), a logarithmic measure of the mean square acoustic pressure.