Physics miscellaneous


  1. Curie point is the temperature at which









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    In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature at which a ferromagnetic or a ferromagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature. The term is also used in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.

    Correct Option: B

    In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature at which a ferromagnetic or a ferromagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature. The term is also used in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.


  1. What changes will happen to a bowl of ice and water kept at exactly zero degree Celsius ?









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    Fresh water cooled to zero (0) degree Celsius and subjected to additional loss of heat energy normally will freeze. A mixture of fresh water and ice has an equilibrium temperature of zero (0) degree Celsius. Adding heat to the mixture causes ice to melt whereas removing heat causes water to freeze. For that reason, 0 (zero) degree Celsius is called the freezing point of fresh water. Cloud droplets can cool well below the usual freezing point while remaining liquid. Such cloud droplets are composed of super cooled water.

    Correct Option: C

    Fresh water cooled to zero (0) degree Celsius and subjected to additional loss of heat energy normally will freeze. A mixture of fresh water and ice has an equilibrium temperature of zero (0) degree Celsius. Adding heat to the mixture causes ice to melt whereas removing heat causes water to freeze. For that reason, 0 (zero) degree Celsius is called the freezing point of fresh water. Cloud droplets can cool well below the usual freezing point while remaining liquid. Such cloud droplets are composed of super cooled water.



  1. The bats can fly in the dark because









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    Bats use echolocation to navigate and forage, often in total darkness. They generally emerge from their roosts in caves, attics, or trees at dusk and hunt for insects into the night. Their use of echolocation allows them to occupy a niche where there are often many insects (that come out at night since there are fewer predators then) and where there is less competition for food, and where there are fewer other species that may prey on the bats themselves. Microbats generate ultrasound via the larynx and emit the sound through the open mouth or, much more rarely, the nose.

    Correct Option: D

    Bats use echolocation to navigate and forage, often in total darkness. They generally emerge from their roosts in caves, attics, or trees at dusk and hunt for insects into the night. Their use of echolocation allows them to occupy a niche where there are often many insects (that come out at night since there are fewer predators then) and where there is less competition for food, and where there are fewer other species that may prey on the bats themselves. Microbats generate ultrasound via the larynx and emit the sound through the open mouth or, much more rarely, the nose.


  1. ATM stands for









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    An automated teller machine or automatic teller machine (ATM) is a computerized telecommuni-cations device that provides the clients of a financial institution with access to financial transactions in a public space without the need for a cashier, human clerk or bank teller. ATMs are known by various other names including ATM machine, automated banking machine, “cash dispenser” (Germany) and various regional variants derived from trademarks on ATM systems held by particular banks.

    Correct Option: A

    An automated teller machine or automatic teller machine (ATM) is a computerized telecommuni-cations device that provides the clients of a financial institution with access to financial transactions in a public space without the need for a cashier, human clerk or bank teller. ATMs are known by various other names including ATM machine, automated banking machine, “cash dispenser” (Germany) and various regional variants derived from trademarks on ATM systems held by particular banks.



  1. The process involved in making soap is









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    Saponification is a process that produces soap, usually from fats and lye. In technical terms, saponification involves base (usually caustic soda NaOH) hydrolysis of triglycerides, which are esters of fatty acids, to form the sodium salt of a carboxylate. In addition to soap, such traditional saponification processes produces glycerol. “Saponifiable substances” are those that can be converted into soap. Vegetable oils and animal fats are the main materials that are saponified. These greasy materials, triesters called triglycerides, are mixtures derived from diverse fatty acids. Triglycerides can be converted to soap in either a one- or a two-step process.

    Correct Option: A

    Saponification is a process that produces soap, usually from fats and lye. In technical terms, saponification involves base (usually caustic soda NaOH) hydrolysis of triglycerides, which are esters of fatty acids, to form the sodium salt of a carboxylate. In addition to soap, such traditional saponification processes produces glycerol. “Saponifiable substances” are those that can be converted into soap. Vegetable oils and animal fats are the main materials that are saponified. These greasy materials, triesters called triglycerides, are mixtures derived from diverse fatty acids. Triglycerides can be converted to soap in either a one- or a two-step process.