Question

Equal lengths of copper, glass, iron, zinc and steel are heated. Which expand the most
(A) $ Zn $
(B) Glass
(C) Iron
(D) Copper

Answer 1

Hint :here we have to tell the material which will expand the most. To answer the question one must be familiar with the thermal expansion property of the material as well as the specific heat of the given. Keeping these two points in find lets solve the given question.

Complete Step By Step Answer:
Specific is the quantity of heat required to raise the temperature of one gram of a substance by one degree $ Celsius $ . In thermodynamics, the specific heat capacity or occasionally mass heat capacity of a substance is the heat capacity of a sample of substance divided by the mass of the substance. The specific heat capacity often varies with temperature and is different for each state of matter. Liquid water has one of the highest specific heat capacities among common substances. For gas specific heat capacity is higher when allowed to expand.
Whenever a substance is undergoing a phase transition its specific heat capacity is infinite because the heat goes into changing its state rather than raising its temperature.
The S.I. unit of specific heat capacity is $ Joule{\text{ }}per{\text{ }}Kelvin{\text{ }}per{\text{ }}Kilogram $ , $ J.k{g^{ - 1}}.{K^{ - 1}} $ .
Thermal expansion is the tendency of matter to change its shape, area, volume, and density in response to a change in temperature and it usually doesn’t include phase transition. In case of solid expansion is directly proportional to temperature change, its volume expands three times and area expands twice as much as the lengths do.
Now that we are familiar with these terms we will solve the given question.
Here all the materials given are solid in state. So let’s explore their specific heat value:
Specific heat of these materials is:
Copper = $ 0.385J/{g^ \circ }C $
Glass= $ 0.84J/{g^ \circ }C $
Iron= $ 0.450J/{g^ \circ }C $
Zinc= $ 0.376J/{g^ \circ }C $
As it is clear from the specific heat value that glass has maximum specific heat value. Therefore our answer is B.

Note :
The value of specific corresponds to the fact that higher the value the more the absorption of heat will take place which further results in more expansion of the material, whereas if the specific value is low it will result in less expansion of that material.