Question

An antifriction alloy made up of antimony with tin and copper, which is extensively used in machine bearings is called:
(A) Duralumin
(B) Babbitt metal
(C) Spiegeleisen
(D) Amalgams

Answer 1

Hint: Read the question and carefully determine the composition of metals present in each option. Find out which alloy is used in machine bearings to obtain the answer.

Complete step by step answer:
Let’s have a look at the given options in the question.
(A) Duralumin: Duralumin is an aluminium alloy composed of 95% aluminium, 3% copper, 1% manganese and 1% magnesium. It is used in aeroplanes and automobile parts due to its light, tough and ductile properties.
(B) Babbitt metal: Babbitt metal is a soft alloy composed of 89% tin, 9% antimony and 2% copper. It is used in machine bearings because of its antifriction property.
(C) Spiegeleisen: Spiegeleisen is a ferromanganese alloy composed of iron in large quantities, 15% manganese, and small quantities of carbon and silicon. This alloy is used in the manufacturing process of steel known as Linz- Donawitz process.
(D) Amalgams: Amalgam is a mercury alloy consisting of any other metal combined with mercury. It can be liquid or solid or a soft paste depending on the composition of mercury in the amalgam. Like we have sodium amalgam alloy in which sodium is combined with mercury.
Therefore, an antifriction alloy made up of antimony with tin and copper, which is extensively used in machine bearings is called Babbitt metal.

So, the correct answer is “Option B”.

Note: Machine bearings are small metal balls made up of Babbitt metal which help in reducing friction while the machine is being operated. Bearings help in reducing friction by using rolling mechanism instead of sliding mechanism and therefore, here the term ‘antifriction’ is used in the question.