Molecular Physics | Thermodynamics Answers

The transfer of heat through radiation is achieved by

Option A. the application of radioactive isotopes.
Option B. warming up the intervening medium.
Option C. not warming up the intervening medium.

In 'standard conditions' what is the standard for measurement of volume and density of a liquid or solid?.
Option A. 20 °C and 760mm of Mercury.
Option B. 0 °C and 760mm of Mercury.
Option C. 20 °C and 700mm of Mercury.

In 'standard conditions' what is the standard for measurement of volume and density of a gas?.
Option A. 0 °C and 760mm of Mercury.
Option B. 20 °C and 700mm of Mercury.
Option C. 20 °C and 760mm of Mercury.

The standard temperature and pressure for measuring the density of liquids is.
Option A. 15 °C and 760 mmHg.
Option B. 0 °C and 760 mmHg.
Option C. 4 °C and 760 mmHg.

Calculate the length of a brass rod which shows the same expansion as an iron rod of length 4m, when both rods are heated through the same range of temperature.
Coefficient of linear expansion of brass is 0.000018 per K and iron is 0.000012 per K.

2- The air in the refrigerator is cooled throughout even though the cooling element is at the top of the refrigerator______

As a block of ice is melted (to 4 °C). Its volume.
Option A. remains the same.
Option B. decreases.
Option C. increases.


Which one is true

In a isothermal process temperature remains constant. According to first law of thermodynamics Q=W+∆U. here ∆U is internal energy. For ideal gas ∆U is function of temperature only hence ∆U=0 for isothermal process. Hence we get Q=W for isothermal process. But according to kelvin-planck statement of second law of thermodynamics heat is not completely convertible into work. Then how this Q=W is possible for isothermal process.

By using the ideal gas equation of state, show that change in the internal energy of the same quantity of an ideal gas in adiabatic process is given by
dU= -NRTlnV