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21
When a spoon is to be electroplated with nickel the spoon is
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Answer & Solution
Answer: Option C
Solution:
Electroplating is the deposition by electrolysis of a coating of metal upon a conducting surface. The simplest system makes the object to be plated the negative electrode (cathode) or plate in a galvanic couple. Thus a spoon or other object may be connected by a wire to a plate of nickel. The process that occurs on the spoon is called reduction and, therefore, the spoon is also referred to as a cathode.
22
Conversion of chemical energy into electrical energy occurs in
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Answer & Solution
Answer: Option C
Solution:
The chemical energy in food is converted by the body into mechanical energy and heat. The chemical energy in coal is converted into electrical energy at a power plant. The chemical energy in a battery can also supply electrical power by means of electrolysis.
23
The process of covering water pipes made of Iron with Zinc layer to prevent corrosion is called :
Discuss
Answer & Solution
Answer: Option D
Solution:
Galvanization or galvanizing (also spelled galvanisation or galvanising) is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which the parts are submerged in a bath of molten hot zinc.
24
Galvanization of iron is carried out using
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Answer & Solution
Answer: Option A
Solution:
Galvanisation or galvanization (or galvanizing as it is most commonly called) is the process of applying a protective zinc coating to iron or steel, to prevent rusting. The most common method is hot dip galvanizing, in which steel sections are submerged in a bath of molten zinc.
25
The working of a dry cell is based on
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Answer & Solution
Answer: Option D
Solution:
A dry cell is a type of battery that uses a paste electrolyte, with only enough moisture to allow current to flow. It works in accordance with Faraday’s law of electrolysis. It consists of an outer case made of zinc (the negative electrode), a carbon rod in the center of the cell (the positive electrode), and the space between them is filled with an electrolyte paste. In operation the electrolyte, causes the electrons to flow and produce electricity.
26
Galvanization is the :
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Answer & Solution
Answer: Option A
Solution:
Galvanisation or galvanization (or galvanizing as it is most commonly called) is the process of applying a protective zinc coating to iron or steel, to prevent rusting. The most common method is hot dip galvanizing, in which steel sections are submerged in a bath of molten zinc.
27
Which one of the following metals is used to galvanise iron ?
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Answer & Solution
Answer: Option C
Solution:
Zinc is used for galvanising iron to protect it from rusting.
28
A non-electronic conductor is
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Answer & Solution
Answer: Option D
Solution:
Either the wording of the question is wrong or it doesn’t have a correct option. A non-conductor is a substance which does not allow the passage of electricity. As a general rule, all metals (Iron, Mercury, etc) are good conductors. Nonmetals are non-conductors, except for carbon in the form of graphite and the gas carbon. Copper Sulphate is a good electrolyte (a liquid which allows the passage of electricity). So all the options given in the question are good electrical conductors.
29
The anode of a dry cell is made up of
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Answer & Solution
Answer: Option C
Solution:
A standard dry cell comprises a zinc anode, usually in the form of a cylindrical pot, with a carbon cathode in the form of a central rod. The electrolyte is ammonium chloride in the form of a paste next to the zinc anode.
30
The coating of a thin layer of zinc on steel or iron objects is known as
Discuss
Answer & Solution
Answer: Option C
Solution:
Galvanisation is a process of protecting iron or steel from rusting by coating them with a thin layer of zinc.