Question

Arrange the following in the decreasing order of effect of thermal expansion in them?

• A. 2 > 4 > 1 > 3
• B. 3 > 2 > 1 > 4
• C. 3 > 1 > 4 > 2

Answer 1

The correct option is C 3 > 1 > 4 > 2

We need to arrange the given objects in the decreasing order of effect of thermal expansion on them.
Let us look at the material used in each of the objects provided.
Copper is used in making electric wires, roof sheets are made up of aluminium and the rim mounted on the cart wheel is made up of steel.
Crockery used in the kitchen is made up of pyrex glass. Smaller the value of the coefficient of linear expansion of a material, lesser will be the effect of thermal expansion seen in that material.
Out of all the options provided, crockery uses pyrex glass which has the lowest value of coefficient of linear expansion and hence will show least effect of thermal expansion.
Only option B has crockery at the last position in the decreasing order of effect of thermal expansion. Therefore option B is the correct option.
Moreover,
${\alpha }_{copper}=17\times {10}^{-6}$${}^{\circ }$C${}^{-1}$
${\alpha }_{aluminium}=24\times {10}^{-6}$${}^{\circ }$C${}^{-1}$
${\alpha }_{steel}=13\times {10}^{-6}$${}^{\circ }$C${}^{-1}$
Therefore aluminium roof sheet will be first in the order, copper wire will stand second, steel rim will be third and crockery will be last in the decreasing order.