Heat and Thermodynamics

The heat absorbed by a system in going through the given cyclic process is :

If the collision frequency of hydrogen molecules in a closed chamber at \(27^{\circ} \mathrm{C}\) is \(\mathrm{Z}\), then the collision frequency of the same system at \(127^{\circ} \mathrm{C}\) is :

If \(\mathrm{n}\) is the number density and \(\mathrm{d}\) is the diameter of the molecule, then the average distance covered by a molecule between two successive collisions (i.e. mean free path) is represented by :

During an adiabatic process, if the pressure of a gas is found to be proportional to the cube of its absolute temperature, then the ratio of \(\frac{\mathrm{C}_{\mathrm{P}}}{\mathrm{C}_{\mathrm{V}}}\) for the gas is :

P-T diagram of an ideal gas having three different densities \(\rho_1, \rho_2, \rho_3\) (in three different cases) is shown in the figure. Which of the following is correct :

On celcius scale the temperature of body increases by \(40^{\circ} \mathrm{C}\). The increase in temperature on Fahrenheit scale is :

The resistances of the platinum wire of a platinum resistance thermometer at the ice point and steam point are \(8 \Omega\) and \(10 \Omega\) respectively. After inserting in a hot bath of temperature \(400^{\circ} \mathrm{C}\), the resista...

A sample of gas at temperature \(T\) is adiabatically expanded to double its volume. Adiabatic constant for the gas is \(\gamma=3 / 2\). The work done by the gas in the process is:
\((\mu=1 \text { mole })\)

The translational degrees of freedom \(\left(f_t\right)\) and rotational degrees of freedom \(\left(f_r\right)\) of \(\mathrm{CH}_4\) molecule are:

The parameter that remains the same for molecules of all gases at a given temperature is :

The given figure represents two isobaric processes for the same mass of an ideal gas, then

A gas mixture consists of 8 moles of argon and 6 moles of oxygen at temperature T. Neglecting all vibrational modes, the total internal energy of the system is:

The speed of sound in oxygen at S.T.P. will be approximately: (given, \(R=8.3 \mathrm{~JK}^{-1}, \gamma=1.4\))

At which temperature the r.m.s. velocity of a hydrogen molecule equal to that of an oxygen molecule at \(47^{\circ} \mathrm{C}\) ?

Two thermodynamical processes are shown in the figure. The molar heat capacity for process A and B are \(\mathrm{C}_{\mathrm{A}}\) and \(\mathrm{C}_{\mathrm{B}}\). The molar heat capacity at constant pressure and constant volume are represe...

If three moles of monoatomic gas \(\left(\gamma=\frac{5}{3}\right)\) is mixed with two moles of a diatomic gas \(\left(\gamma=\frac{7}{5}\right)\), the value of adiabatic exponent \(\gamma\) for the mixture is

A block of ice at \(-10^{\circ} \mathrm{C}\) is slowly heated and converted to steam at \(100^{\circ} \mathrm{C}\). Which of the following curves represent the phenomenon qualitatively:

Choose the correct statement for processes A & B shown in figure.

Two vessels \(A\) and \(B\) are of the same size and are at same temperature. A contains \(1 \mathrm{~g}\) of hydrogen and \(B\) contains \(1 \mathrm{~g}\) of oxygen. \(\mathrm{P}_{\mathrm{A}}\) and \(\mathrm{P}_{\mathrm{B}}\) are the press...

A thermodynamic system is taken from an original state \(\mathrm{A}\) to an intermediate state \(B\) by a linear process as shown in the figure. It's volume is then reduced to the original value from \(\mathrm{B}\) to \(\mathrm{C}\) by an i...

\(N\) moles of a polyatomic gas \((f=6)\) must be mixed with two moles of a monoatomic gas so that the mixture behaves as a diatomic gas. The value of \(N\) is :

The temperature of a gas having \(2.0 \times 10^{25}\) molecules per cubic meter at \(1.38 \mathrm{~atm}\) (Given, \(\mathrm{k}=1.38 \times 10^{-23} \mathrm{JK}^{-1}\)) is :

The average kinetic energy of a monatomic molecule is \(0.414 \mathrm{~eV}\) at temperature :
(Use \(K_B=1.38 \times 10^{-23} \mathrm{~J} / \mathrm{mol}-\mathrm{K}\))

\(0.08 \mathrm{~kg}\) air is heated at constant volume through \(5^{\circ} \mathrm{C}\). The specific heat of air at constant volume is \(0.17 \mathrm{~kcal} / \mathrm{kg}^{\circ} \mathrm{C}\) and \(\mathrm{J}=4.18\) joule/\(\mathrm{~cal}\)...

The total kinetic energy of 1 mole of oxygen at \(27^{\circ} \mathrm{C}\) is :
[Use universal gas constant \((R)=8.31 \mathrm{~J} /\) mole K]

The equation of state of a real gas is given by \(\left(\mathrm{P}+\frac{\mathrm{a}}{\mathrm{V}^2}\right)(\mathrm{V}-\mathrm{b})=\mathrm{RT}\), where \(\mathrm{P}, \mathrm{V}\) and \(\mathrm{T}\) are pressure, volume and temperature respect...

During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute temperature. The ratio of \(\frac{\mathrm{Cp}}{\mathrm{Cv}}\) for the gas is :

The pressure and volume of an ideal gas are related as $\mathrm{PV}^{\frac{3}{2}}=\mathrm{K}$ (Constant). The work done when the gas is taken from state $A\left(P_1, V_1, T_1\right)$ to state $B\left(P_2, V_2, T_2\right)$ is :

Two moles a monoatomic gas is mixed with six moles of a diatomic gas. The molar specific heat of the mixture at constant volume is :

If the root mean square velocity of hydrogen molecule at a given temperature and pressure is $2 \mathrm{~km} / \mathrm{s}$, the root mean square velocity of oxygen at the same condition in $\mathrm{km} / \mathrm{s}$ is :

A diatomic gas $(\gamma=1.4)$ does $200 \mathrm{~J}$ of work when it is expanded isobarically. The heat given to the gas in the process is :

Given below are two statements:
Statement I: If heat is added to a system, its temperature must increase.
Statement II: If positive work is done by a system in a thermodynamic process, its volume must increase.
In the light of the above sta...

A steel rod of length \(1 \mathrm{~m}\) and cross sectional area \(10^{-4} \mathrm{~m}^{2}\) is heated from \(0^{\circ} \mathrm{C}\) to \(200^{\circ} \mathrm{C}\) without being allowed to extend or bend. The compressive tension produced in ...

Work done by a Carnot engine operating between temperatures \(127^{\circ} \mathrm{C}\) and \(27^{\circ} \mathrm{C}\) is \(2 \mathrm{~kJ}\). The amount of heat transferred to the engine by the reservoir is :

The temperature at which the kinetic energy of oxygen molecules becomes double than its value at \(27^{\circ} \mathrm{C}\) is

The number of air molecules per cm\(^3\) increased from \(3\times10^{19}\) to \(12\times10^{19}\). The ratio of collision frequency of air molecules before and after the increase in number respectively is:

A source supplies heat to a system at the rate of \(1000 \mathrm{~W}\). If the system performs work at a rate of \(200 \mathrm{~W}\). The rate at which internal energy of the system increases is

The ratio of speed of sound in hydrogen gas to the speed of sound in oxygen gas at the same temperature is:

A body cools in 7 minutes from \(60^{\circ} \mathrm{C}\) to \(40^{\circ} \mathrm{C}\). The temperature of the surrounding is \(10^{\circ} \mathrm{C}\). The temperature of the body after the next 7 minutes will be:

The temperature of an ideal gas is increased from \(200 \mathrm{~K}\) to \(800 \mathrm{~K}\). If r.m.s. speed of gas at \(200 \mathrm{~K}\) is \(v_{0}\). Then, r.m.s. speed of the gas at \(800 \mathrm{~K}\) will be:

The correct relation between \(\gamma = {{{c_p}} \over {{c_v}}}\) and temperature T is :

The pressure of a gas changes linearly with volume from \(\mathrm{A}\) to \(\mathrm{B}\) as shown in figure. If no heat is supplied to or extracted from the gas then change in the internal energy of the gas will be

A water heater of power $2000 \mathrm{~W}$ is used to heat water. The specific heat capacity of water is $4200 \mathrm{~J}$ $\mathrm{kg}^{-1} \mathrm{~K}^{-1}$. The efficiency of heater is $70 \%$. Time required to heat $2 \mathrm{~kg}$ of ...

A hypothetical gas expands adiabatically such that its volume changes from 08 litres to 27 litres. If the ratio of final pressure of the gas to initial pressure of the gas is $\frac{16}{81}$. Then the ratio of $\frac{\mathrm{Cp}}{\mathrm{Cv...

Heat energy of $735 \mathrm{~J}$ is given to a diatomic gas allowing the gas to expand at constant pressure.

Each gas molecule rotates around an internal axis but do not oscillate. The increase in the internal

energy of the gas will be :

Heat is given to an ideal gas in an isothermal process.
A. Internal energy of the gas will decrease.
B. Internal energy of the gas will increase.
C. Internal energy of the gas will not change.
D. The gas will do positive work.
E. The gas wi...

The pressure \((\mathrm{P})\) and temperature (\(\mathrm{T})\) relationship of an ideal gas obeys the equation

\(\mathrm{PT}^{2}=\) constant. The volume expansion coefficient of the gas will be :

A faulty thermometer reads $5^{\circ} \mathrm{C}$ in melting ice and $95^{\circ} \mathrm{C}$ in stream. The correct temperature on absolute scale will be __________ $\mathrm{K}$ when the faulty thermometer reads $41^{\circ} \mathrm{C}$.

A flask contains hydrogen and oxygen in the ratio of $2: 1$ by mass at temperature $27^{\circ} \mathrm{C}$. The ratio of average kinetic energy per molecule of hydrogen and oxygen respectively is:

Given below are two statements: one is labelled as Assertion $\mathbf{A}$ and the other is labelled as Reason $\mathbf{R}$
Assertion A: Efficiency of a reversible heat engine will be highest at $-273^{\circ} \mathrm{C}$ temperature of cold ...