Which metal is the best conductor of electricity?
- A.Copper
- B.Aluminium
- C.Silver
- D.Gold
Correct answer
Explanation
The correct answer is C, silver. Silver has the highest electrical conductivity of all metals and also the highest thermal conductivity, but it is costly and tarnishes, so it is used only in specialised contacts and instruments. Option A, copper, comes next and is the metal actually used for household and industrial wiring, because it combines high conductivity with reasonable cost and good ductility; students who answer from everyday use rather than from the property pick this one. Option B, aluminium, is a lighter and cheaper conductor used for overhead transmission lines, where weight matters more than conductivity per unit area. Option D, gold, conducts well and does not corrode, so it is used to plate delicate electronic contacts, but it ranks below silver and copper. Remember the order: silver, then copper, then gold, then aluminium.
Read the full article: Metals and Non-Metals: Properties, Ores and Alloys
Practice Questions
View allCalamine is an ore of:
- A.Tin
- B.Magnesium
- C.Zinc
- D.Copper
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Calamine is zinc carbonate, and since it is a carbonate ore it is converted to the oxide by calcination, that is by heating in the absence of air, before being reduced to the metal.
Read the full explanation →Which of the following is NOT an alloy?
- A.Solder
- B.Silver
- C.Bronze
- D.Brass
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Silver is an element, a pure metal with its own place in the periodic table, so it cannot be an alloy; an alloy is a homogeneous mixture of two or more metals, or of a metal with a non-metal such as carbon.
Read the full explanation →Which of the following is the most ductile metal?
- A.Gold
- B.Copper
- C.Silver
- D.Iron
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Ductility is the property of being drawn into a wire, and gold is the most ductile metal known; it is also the most malleable, so a very small quantity can be beaten into an extremely thin sheet or drawn into a very long wire.
Read the full explanation →Brass is an alloy of:
- A.copper and tin
- B.copper and nickel
- C.copper and iron
- D.copper and zinc
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Brass takes the workability of copper and the hardness of zinc, resists corrosion and is easy to cast, which is why it is used for utensils, locks, taps, fittings and wind instruments.
Read the full explanation →Which metal is in the liquid state at room temperature?
- A.Sodium
- B.Mercury
- C.Lead
- D.Tungsten
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Mercury is the only metal that is liquid at ordinary room temperature, which is why it was long used in thermometers and barometers; it is also the metal that forms amalgams, alloys in which mercury is one component.
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