Question

The iron blade has a ring in which the wooden handle is fixed. The ring is slightly smaller in size than a wooden handle. The ring is heated. When the ring cools, it ______________ and tightly fits on the handle.
A. Contracts
B. Expands
C. Evaporates
D. Condenses

Answer 1

Hint: When any material is heated, the kinetic energy of molecules increased.Molecules and atoms of that specific material move fast and increase.
This heat of material is not enough to break the bond.

Complete answer:
When the metal heated, the length, surface area, volume of the metal also increased. The increase in temperature which results in metal expands and this expansion is termed as the thermal expansion of metal i.e. expansion in metal due to the heating effect.
So, the iron blade has a ring in which the wooden handle is fixed. The ring is slightly smaller in size than a wooden handle. When the ring is heated which is made up of metal expands, after the ring cools, it tightly fits in the wooden handle.

So, the correct answer is “Option C”.

Additional Information:
Thermal expansion is the tendency of some materials to expand when they heat up. When solid materials are heated they absorb thermal energy, their molecules enter into an excited state. When the energy builds to certain, individual molecules start to shift position and move away from each other—causing the material to expand.
For materials with a lower melting point, thermal expansion isn’t often an issue; such materials turn to liquid rather than expanding. However, many metals have a high enough melting point that expansion can be a serious problem because large amount of energy is required for heating which is not possible in some cases

Note:
Note that the concept of thermal expansion must be known in case of solid to solve this problem. This phenomenon has many applications in our day to day life e.g. in railway track, pebbles are used to overcome this thermal expansion.
When materials are heated the kinetic energy associated with it . It is defined as the energy which is possessed by molecules when they are in State of motion.


Mathematically expression of Kinetic Energy
$\text{K}\text{.E}=\dfrac{1}{2}\text{m}{{\text{v}}^{2}}$
Where,
K.E is the kinetic energy of the object.
m is the mass of an object
v is the velocity of an object