a closed system undergoes a process 1 to 2 for which the

A closed system undergoes a process $$1 \to 2$$ for which the values $${W_{1 - 2}}$$ and $${Q_{1 - 2}}$$ are $$50\,kJ$$ and $$- 20\,kJ$$ respectively. If the system is returned to state 1 and $${Q_{2 \to 1}}$$ is $$+ 10\,kJ$$ the work done $${W_{2 \to 1}}$$ is

A. $$40\,kJ$$

B. $$50\,kJ$$

C. $$-60\,kJ$$

D. $$-50\,kJ$$

Answer : $$-60\,kJ$$

Solution :
$$\eqalign{ & - 20 = \Delta U + 50 \Rightarrow \Delta U = - 70. \cr & {\text{From}}\,\,2 \to 1,\,\Delta U = 70\,kJ. \cr & {\text{Now}}\,\,10 = 70 + W \Rightarrow W = - 60\,kJ. \cr} $$

Releted MCQ Question on
Heat and Thermodynamics >> Thermodynamics

Releted Question 1

An ideal monatomic gas is taken round the cycle $$ABCDA$$ as shown in the $$P - V$$ diagram (see Fig.). The work done during the cycle is

A. $$PV$$

B. $$2PV$$

C. $$\frac{1}{2}PV$$

D. zero

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Releted Question 2

If one mole of a monatomic gas $$\left( {\gamma = \frac{5}{3}} \right)$$ is mixed with one mole of a diatomic gas $$\left( {\gamma = \frac{7}{5}} \right)$$ the value of $$\gamma $$ for mixture is

A. 1.40

B. 1.50

C. 1.53

D. 3.07

View Answer

Releted Question 3

A closed compartment containing gas is moving with some acceleration in horizontal direction. Neglect effect of gravity. Then the pressure in the compartment is

A. same everywhere

B. lower in the front side

C. lower in the rear side

D. lower in the upper side

View Answer

Releted Question 4

A gas mixture consists of 2 moles of oxygen and 4 moles of argon at temperature $$T.$$ Neglecting all vibrational modes, the total internal energy of the system is

A. $$4\, RT$$

B. $$15\, RT$$

C. $$9\, RT$$

D. $$11\, RT$$

View Answer

A closed system undergoes a process $$1 \to 2$$ for which the values $${W_{1 - 2}}$$ and $${Q_{1 - 2}}$$ are $$50\,kJ$$ and $$- 20\,kJ$$ respectively. If the system is returned to state 1 and $${Q_{2 \to 1}}$$ is $$+ 10\,kJ$$ the work done $${W_{2 \to 1}}$$ is

Releted MCQ Question on
Heat and Thermodynamics >> Thermodynamics

An ideal monatomic gas is taken round the cycle $$ABCDA$$ as shown in the $$P - V$$ diagram (see Fig.). The work done during the cycle is

If one mole of a monatomic gas $$\left( {\gamma = \frac{5}{3}} \right)$$ is mixed with one mole of a diatomic gas $$\left( {\gamma = \frac{7}{5}} \right)$$ the value of $$\gamma $$ for mixture is

A closed compartment containing gas is moving with some acceleration in horizontal direction. Neglect effect of gravity. Then the pressure in the compartment is

A gas mixture consists of 2 moles of oxygen and 4 moles of argon at temperature $$T.$$ Neglecting all vibrational modes, the total internal energy of the system is

Practice More Releted MCQ Question on
Thermodynamics

Practice More MCQ Question on Physics Section

A closed system undergoes a process $$1 \to 2$$ for which the values $${W_{1 - 2}}$$ and $${Q_{1 - 2}}$$ are $$50\,kJ$$ and $$- 20\,kJ$$ respectively. If the system is returned to state 1 and $${Q_{2 \to 1}}$$ is $$+ 10\,kJ$$ the work done $${W_{2 \to 1}}$$ is

Releted MCQ Question on Heat and Thermodynamics >> Thermodynamics

An ideal monatomic gas is taken round the cycle $$ABCDA$$ as shown in the $$P - V$$ diagram (see Fig.). The work done during the cycle is

If one mole of a monatomic gas $$\left( {\gamma = \frac{5}{3}} \right)$$ is mixed with one mole of a diatomic gas $$\left( {\gamma = \frac{7}{5}} \right)$$ the value of $$\gamma $$ for mixture is

A closed compartment containing gas is moving with some acceleration in horizontal direction. Neglect effect of gravity. Then the pressure in the compartment is

A gas mixture consists of 2 moles of oxygen and 4 moles of argon at temperature $$T.$$ Neglecting all vibrational modes, the total internal energy of the system is

Practice More Releted MCQ Question on Thermodynamics

Practice More MCQ Question on Physics Section

Releted MCQ Question on
Heat and Thermodynamics >> Thermodynamics

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Thermodynamics