2nd Law of Thermodynamics

Q. Find the change in the entropy in the following process 100 gm of ice at $0^{\circ }C$ melts when dropped in a bucket of water at ${50}^{\circ }C$ (Assume temperature of water does not change)

1. +5.4 cal/K
2. – 5.4 cal/K
3. – 4.5 cal/K
4. + 4.5 cal/K

Q. Assertion: A room can be cooled by opening the door of a refrigerator in a closed room.
Reason: Heat flows from lower temperature (refrigerator) to higher temperature (room).

1. If both assertion and reason are true but reason is not the correct explanation of the assertion.
2. If both assertion and reason are true and the reason is the correct explanation of the assertion.
3. If the assertion and reason both are false.
4. If assertion is true but reason is false.
5. If assertion is false but reason is true.

Q. Which of the following statements is correct according to the second law of thermodynamics?

1. All heat can be converted into work
2. All heat cannot be converted into work
3. Both (a) and (b) are correct.
4. Both (a) and (b) are wrong.

Q. Which of the following statement is true as per the second law of thermodynamics for an isolated, ordered system?

1. Heat will flow into the system
2. Heat will flow out of the system
3. Work will be done by the system
4. Work will be done on the system
5. The entropy withing the system will increase

Q. For the conversion of liquid into a solid :

1. orderliness decreases and entropy decreases
2. orderliness increases and entropy decreases
3. both are not related
4. orderliness increases and entropy increases

Q. Heat cannot by itself flow from a body at lower temperature to a body at higher temperature is a statement of consequence of

1. second law of thermodynamics
2. conservation of momentum
3. first law of thermodynamics.
4. conservation of mass

Q. One mole of oxygen is expanded from a volume 1 $\ell$ to 2$\ell$ at a constant temperature $T=280K$. Find the change in internal energy of the gas.

1. $9.8kJ$
2. $0kJ$
3. $12.8kJ$
4. $2.8kJ$

Q. Which of the following expressions is known as Clausius inequality?

1. $\oint \frac{dq}{T}\le 0$
2. $\oint \frac{dq}{T}=0$
3. $\oint \frac{T}{dq}\le 0$
4. $\oint \frac{dq}{T}\ge \le 0$

Q. Which statement is true for second law of thermodynamics ?

1. Heat can flow spontaneously from a cold object to a hot object.
2. You can not create a heat engine which extracts heat and converts it all to useful work.
3. According to Plank-Kelvin's law under some circumstances a perfect heat engine is possible.
4. None of these.

Q. Which of the following is not a path function ?

1. $\Delta$ Q
2. $\Delta$ Q + $\Delta$ W
3. $\Delta$ W
4. $\Delta$ Q - $\Delta$ W