Choose the correct statements(s) from the following:
Choose the correct statements(s) from the following:
The correct options are
A A temperature change which increases the length of a steel rod by 0.1% will increase its volume by nearly 0.3%
B The specific heat of a solid is different when the solid is heat at (a) constant pressure and (b) the constant volume
D When the distance between two fixed points is measured with a steel tape, the observed reading will be less on a hot day than on a cold day.
Statement (a) is correct because the coefficient of volume expansion is very nearly three times the coefficient of linear expansion. Statement (b) is also correct. When a solid is heated at constant pressure, it does expand a little and some heat is required for doing the mechanical work associated with this expansion. The difference between the two specific heats (at constant pressure and at constant volume) is small enough to be generally neglected for solids and liquids. This difference is large for gases. Statement (c) is incorrect. The thermal conductivity of air is less than that of wool. Yet we prefer wool which traps pockets of air between its fibres. These air pockets cannot carry heat by convection either. Statement (d) is correct, because of the expansion of steel tap on a hot day, the markings on the tape would be farther apart than on a cold day.
A
A temperature change which increases the length of a steel rod by 0.1% will increase its volume by nearly 0.3%
B
The specific heat of a solid is different when the solid is heat at (a) constant pressure and (b) the constant volume
D
When the distance between two fixed points is measured with a steel tape, the observed reading will be less on a hot day than on a cold day.
Statement (a) is correct because the coefficient of volume expansion is very nearly three times the coefficient of linear expansion. Statement (b) is also correct. When a solid is heated at constant pressure, it does expand a little and some heat is required for doing the mechanical work associated with this expansion. The difference between the two specific heats (at constant pressure and at constant volume) is small enough to be generally neglected for solids and liquids. This difference is large for gases. Statement (c) is incorrect. The thermal conductivity of air is less than that of wool. Yet we prefer wool which traps pockets of air between its fibres. These air pockets cannot carry heat by convection either. Statement (d) is correct, because of the expansion of steel tap on a hot day, the markings on the tape would be farther apart than on a cold day.
