Question

Why is 'invar' used for making the pendulum of a clock.

Answer 1

Hint: We can use the fact that Invar, also known generically as FeNi36 (64FeNi in the US), is a nickel-iron alloy notable for its uniquely low coefficient of thermal expansion (CTE or $\alpha$ ). The name Invar comes from the word invariable, referring to its relative lack of expansion or contraction with temperature changes. Invar, alloy of iron that expands very little when heated; it contains 64 percent iron and 36 percent nickel. Invar was formerly used for absolute standards of length measurement and is now used for surveying tapes and in watches and various other temperature-sensitive devices.

Complete step by step answer
It can be said that the pendulum clock is made up of invar because invar's coefficient of thermal expansion is small. So, the length of the pendulum remains unaffected during changes in temperature. Invar is derived from the word invariable. It is an alloy which is made from nickel and iron. It has a low coefficient of thermal expansion. So, there will not be linear expansion of the pendulum due to the rise in temperature. And the time shown in the clock will be accurate. Thus, invar is used in the pendulum of the clock. Invar, also known as Nickel Alloy 36, is a nickel-iron alloy noted for its uniquely low coefficient of thermal expansion. Invar is therefore always magnetic in the temperature range in which it exhibits the low expansion characteristics.

Note: We can conclude that Invar can be made in Thermal Foundation by mixing Iron and Nickel dust. Then smelt the resulting blend into Invar ingots. Or else, the invar ingots can be created directly in an Induction Smelter. Invar alloys are widely known and utilized because they exhibit a coefficient of thermal expansion (CTE) that is close to zero. The fact that Invar maintains this low CTE over room temperature has made it one of the most effective alloys for use in precision instruments. Invar Blend is a mixed dust acquired from crafting 2 of either Iron Dust or Pulverized Iron, and 1 Pulverized Ferrous Metal together, producing 3 Invar Blend. Invar Blend can be then smelted into Invar Ingots, which are used in a few Thermal Expansion recipes.