GENERAL KNOWLEDGE

Detailed explanation-1: -The intermolecular changes due to heat lead to the expansion of the iron. Therefore, there is an increase in the length of the strip.

Detailed explanation-2: -Length, surface area and volume will increase with temperature. The scientific term for this is thermal expansion. The degree of thermal expansion varies with different types of metal. Thermal expansion occurs because heat increases the vibrations of the atoms in the metal.

Detailed explanation-3: -As the temperature of a material increases, it begins to expand. For instance, a metal rod or beam will increase its length by an amount ∆L. The value of ∆L depends on the original length (Lo) at the original temperature (To), the temperature to which it is heated (T) and the coefficient of linear expansion ().

Detailed explanation-4: -At room temperature, the iron atoms are in an unusual loosely packed open arrangement; as iron is heated past 912 degrees Celsius, the atoms become more closely packed before loosening again at 1, 394 degrees Celsius and ultimately melting at 1, 538 degrees Celsius.

Detailed explanation-5: -Gases expand the most upon heating because the intermolecular space is more than in solids or liquids.