Work

Q.

In a P-V graph if the initial state is further away from the y axis than the final state, which of these statements is true?

1. The work done by the gas is positive

2. The work done by the gas is zero

3. The work done by the gas is negative

4. No generalized statement can be made

Q.

10 moles of oxygen $(O_2$) gas is being expanded in a container, maintained at a constant pressure, by supplying 500J of heat. What is the rise in the gas' temperature? Assume the atoms do not oscillate along the bond axis, and the gas is pretty much ideal

1. 8.64 K

2. 1.72 K

3. 2.35 K

4. 24.7 K

Q.

What would be the work done by the gas if the entire process is reversed (3 - 2 - 1)?

1. -30 J

2. -22.5 J

3. 30 J

4. 22.5 J

Q.

A bubble of 5.00 mol of helium is submerged at a certain depth in liquid water when the water (and thus the helium) undergoes a temperature increase $\Delta T$ of ${20.0}^{\circ }C$; at constant pressure. As a result, the bubble expands. The helium is monoatomic and ideal. How much work W is done by the helium as it expands against the pressure of the surrounding water during the temperature increase? Use the first law of thermodynamics.​

1. 820 J

2. 831 J

3. 883 J

4. 805 J

Q.

Consider the set up shown, where we have an ideal gas trapped in a cylindrical container, kept on a thermal reservoir which provides heat to the system. The weight on top maintains a constant pressure P on the gas. Supplying heat Q changes the temperature by $\Delta T$, and expands the volume by $\Delta V$. The expanding gas displaces the container and does work, W. Choose the correct inferences from the following options

1. $Q=n{C}_p\Delta T$

2. $W=nR\Delta T$

3. $\text{Increase in internal energy,}$ $\Delta E_{int}=n(C_p-R)\Delta T$

4. $\text{Increase in internal energy,}$ $\Delta E_{int}=n{C}_v\Delta T$.

Q.

Calculate the work done by an ideal gas as it is taken through the process (1 - 2 - 3) as shown in the graph below.

1. 20 J

2. 22.5 J

3. 30 J

4. 45 J

Q. A cylinder of mass 1kg is given heat of 20000 J at atmospheric pressure. If initially temperature of cylinder is ${20}^{\circ }C$, then work done by the cylinder will be (Given that Specific heat of cylinder $=400Jk{g}^{-1}$, Coefficient of volume expansion $=9\times {10}^{-5}{}^{\circ }{C}^{-1}$, Atmospheric pressure $={10}^{5}N/m^2$ and density of cylinder 9000 $kg/m^3$)

1. 0.1 J
2. 0.02 J
3. 0.05 J
4. 0.08 J

Q. In the indicator diagram, net amount of work done will be

1. Infinity
2. negative
3. positive
4. zero

Q. One mole of $O_2$ gas having a volume equal to 22.4 litres at $0^{\circ }$ C and 1 atmospheric pressure in compressed isothermally so that its volume reduces to 11.2 litres. The work done in this process is

1. -1728 J
2. -1572.5 J
3. 1672.5 J
4. 1728 J

Q. Work done by a system under isothermal change from a volume $V_{1}to{V}_2$ for a gas which obeys Vander Waal's equation $(V-\beta n)(P+\frac{a{n}^2}{V})=nRT$

1. 
2. 
3. 
4.