Physics miscellaneous


  1. The term ‘equinox’ means









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    The name “equinox” is derived from the Latin aequus (equal) and nox (night), because around the equinox, the night and day have approximately equal length. An equinox occurs twice a year (around 20 March and 22 September), when the tilt of the Earth’s axis is inclined neither away from nor towards the Sun, the center of the Sun being in the same plane as the Earth’s equator. The term equinox can also be used in a broader sense, meaning the date when such a passage happens. The equinoxes are the only times when the sub-solar point is on the Equator. This point (the place on the Earth’s surface where the center of the Sun can be observed exactly overhead) crosses the Equator moving northward at the March equinox and crosses the Equator moving southward at the September equinox.

    Correct Option: C

    The name “equinox” is derived from the Latin aequus (equal) and nox (night), because around the equinox, the night and day have approximately equal length. An equinox occurs twice a year (around 20 March and 22 September), when the tilt of the Earth’s axis is inclined neither away from nor towards the Sun, the center of the Sun being in the same plane as the Earth’s equator. The term equinox can also be used in a broader sense, meaning the date when such a passage happens. The equinoxes are the only times when the sub-solar point is on the Equator. This point (the place on the Earth’s surface where the center of the Sun can be observed exactly overhead) crosses the Equator moving northward at the March equinox and crosses the Equator moving southward at the September equinox.


  1. Solar energy is converted into chemical energy during









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    In photosynthesis, solar energy is converted to chemical energy. The chemical energy is stored in the form of glucose (sugar). Carbon dioxide, water, and sunlight are used to produce glucose, oxygen, and water. Photosynthesis is a process used by plants and other organisms to convert the light energy captured from the sun into chemical energy that can be used to fuel the organism’s activities. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photo-autotrophs, since they can create their own food. In plants, algae, and cyanobacteria, photosynthesis uses carbon dioxide and water, releasing oxygen as a waste product. Photosynthesis is vital for all aerobic life on Earth.

    Correct Option: B

    In photosynthesis, solar energy is converted to chemical energy. The chemical energy is stored in the form of glucose (sugar). Carbon dioxide, water, and sunlight are used to produce glucose, oxygen, and water. Photosynthesis is a process used by plants and other organisms to convert the light energy captured from the sun into chemical energy that can be used to fuel the organism’s activities. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photo-autotrophs, since they can create their own food. In plants, algae, and cyanobacteria, photosynthesis uses carbon dioxide and water, releasing oxygen as a waste product. Photosynthesis is vital for all aerobic life on Earth.



  1. Which of the following is a nonrenewable source of energy ?









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    A non-renewable resource is a natural resource which cannot be reproduced, grown, generated, or used on a scale which can sustain its consumption rate. So, coal is non-renewable source of energy. Once it is depleted, there is no more available for future needs. Fossil fuels (such as coal, petroleum, and natural gas), nuclear power (uranium) and certain aquifers are examples of non-renewable resources. In contrast, resources such as timber (when harvested sustainably) and wind (used to power energy conversion systems) are considered renewable resources. Natural resources such as coal, petroleum (crude oil) and natural gas take thousands of years to form naturally and cannot be replaced as fast as they are being consumed.

    Correct Option: D

    A non-renewable resource is a natural resource which cannot be reproduced, grown, generated, or used on a scale which can sustain its consumption rate. So, coal is non-renewable source of energy. Once it is depleted, there is no more available for future needs. Fossil fuels (such as coal, petroleum, and natural gas), nuclear power (uranium) and certain aquifers are examples of non-renewable resources. In contrast, resources such as timber (when harvested sustainably) and wind (used to power energy conversion systems) are considered renewable resources. Natural resources such as coal, petroleum (crude oil) and natural gas take thousands of years to form naturally and cannot be replaced as fast as they are being consumed.


  1. Good conductor of electricity is









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    Graphite has a tendency to behave very much like a metal because the carbon molecules arrange themselves into a lattice structure. The crystal lattice is the same orientation that metal forms, and it allows the free-movement of electrons, making it a good electrical conductor. The characteristics possesses by the graphite for conduction is far better than the dry air paper and kerosene and that’s what makes it a good conductor.

    Correct Option: D

    Graphite has a tendency to behave very much like a metal because the carbon molecules arrange themselves into a lattice structure. The crystal lattice is the same orientation that metal forms, and it allows the free-movement of electrons, making it a good electrical conductor. The characteristics possesses by the graphite for conduction is far better than the dry air paper and kerosene and that’s what makes it a good conductor.



  1. When the barometer reading dips suddenly, it is an indication of









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    Sudden and great fluctuations of the barometer at any time of the year indicate unsettled weather for several days, perhaps a fortnight. If the barometer falls two or three-tenths of an inch in four hours, one can expect a gale of wind. If the surface of the mercury in the cistern of the barometer vibrates upon the approach of a storm, the gale can be expected to be severe. In summer, when the barometer falls suddenly, a thunderstorm can be expected, and if it does not rise again upon its cessation, the weather will probably continue unsettled for several days.

    Correct Option: C

    Sudden and great fluctuations of the barometer at any time of the year indicate unsettled weather for several days, perhaps a fortnight. If the barometer falls two or three-tenths of an inch in four hours, one can expect a gale of wind. If the surface of the mercury in the cistern of the barometer vibrates upon the approach of a storm, the gale can be expected to be severe. In summer, when the barometer falls suddenly, a thunderstorm can be expected, and if it does not rise again upon its cessation, the weather will probably continue unsettled for several days.