Why do jewellery makers electroplate gold or silver on metals?
(A) To protect it from corrosion
(B) To protect spoilage of jewellery
(C) To make it shine
(D) To reduce cost

Hint Electroplating is the coating of metal objects with a thin layer of a different metal. It is possible to electroplate coatings of most pure metals and even some alloys. It is a quick and easy process and does not require major investment in costly equipment. It can be done successfully with very simple and basic equipment.

Complete step by step answer
Electroplating is a method to put a metal coating onto an object by placing it in a solution containing metal to be plated and passing electrical current through a piece in the solution. A wide range of colour can be achieved by co-depositing gold with other metals.
There are various types of electroplating such as copper plating, silver plating and chromium plating. However, electroplating allows manufacturers to use inexpensive metals such as steel or zinc for the majority of product and then apply different metals outside, to account for appearance, protection and other properties desired for the product.

Moreover, the jewellery makes electroplate silver and gold on less expensive metals. These elements have the appearance of silver or gold but are much less expensive.

We know that gold plating can be added to almost any metal including brass, copper or nickel but afterwards, a plate of nickel is also added to improve the bond and strengthen the barrier.

Hence, option D is correct.

Note If the metal is only electroplated with gold, then it has zero intrinsic value and is only worth its decorative value. Further, there are many disadvantages of electroplating such as the disposal of waste products that are produced during this process is a major problem and the process requires multiple coating of metal which is a time consuming process.