Question Discussion & Solution

President is the head of the Union Executive of a country.

Similarly,

The correct answer is Esterification.

Key Points

• Esterification -
  • Acid + Alcohol = Ester
  • It is a chemical reaction that forms at least one ester.
  • Esters are produced when acids are heated with alcohol.

Additional Information

• Crystallization -
  • The process of obtaining a pure solid in the form of crystals from a saturated solution is called crystallization.
  • In crystallization, the solution is first evaporated to separate a solid from the solution.
  • When the solution becomes very concentrated, the solution is cooled slowly by stopping evaporation, causing crystals to form.
• Saponification -
  • The saponification of a fat or oil is done by using NaOH solution for the hot process.
  • Saponification to the sodium salt of myristic acid takes place with NaOH in water.
  • Soap is formed by a chemical reaction by heating an aqueous solution of vegetable oil or fat and caustic soda or caustic potash, and glycerol is liberated.

Here the pattern is,

4320 ÷ 6 = 720,

720 ÷ 5 = 144,

144 ÷ 4 = 36,

36 ÷ 3 = 12,

12 ÷ 2 = 6

The correct answer is Electric Heater.

Key Points

• Electric Heater is a device that can convert Electric energy into heat energy.
• In an electron tube, an electric heating element shaped in the form of a wire or ribbon is used to supply heat to a cathode; the element provides heat when a current is passed through it.
• Electric heaters also are used for domestic central heating and for materials processing in the industry for example heat pumps; electric furnace.

Additional Information

• Energy is the ability to do work.
• The  Law of conservation of energy:
  • Energy can neither be created nor be destroyed, only Energy can be converted from one form to another.
• These are some parts of the energy that convert one form to another:
  • Heat
  • Light
  • Motion
  • Electrical
  • Chemical
  • Gravitational

Important Points

The correct answer is Concave lens.

Key Points

• To treat the eye disease known as myopia or nearsightedness we use the Concave Lens.
• A concave lens is a category of lens that deviates a straight light beam coming from the origin to a diminished, upright, virtual image.
• It can construct both real and virtual images.
• The convex lens is a lens that tends to meet at a point of rays of light that convey parallel to its principal axis which is comparatively thick across the middle and thin at the lower and upper edges.
• A convex lens is used in cameras, correction of Hyperopia, etc.
• Bifocal lenses hold two different prescriptions, an upper part to allow for distance vision and an additional power on the bottom part of the lens to help in close-up focus.
• A bifocal lens is used in people suffering from presbyopia, myopia, hyperopia, and astigmatism.
• The result is eyesight lucidity at both distance and near with one pair of glasses.
• A Compound lens is simple lenses made on a general axis usually in close proximity and often cemented with each other.

Additional Information