List of top Physics Questions on Laws of thermodynamics

The volume of an ideal gas increases \( 8 \) times and the temperature becomes \( \frac{1}{4} \) of the initial temperature during a reversible change.

If there is no exchange of heat in this process \( (\Delta Q = 0) \), then identify the gas from the following options (assuming the gases given in the options are ideal gases):
The gas that gives the highest fractional conversion of heat to work in an isobaric process is:
The zeroth law of thermodynamics leads to the concept of
A certain amount of gas of volume $V$ at $27^{\circ} C$ temperature and pressure $2 \times 10^7 Nm ^{-2}$ expands isothermally until its volume gets doubled Later it expands adiabatically until its volume gets redoubled The final pressure of the gas will be (Use $\gamma=15$ )

A unit scale is to be prepared whose length does not change with temperature and remains $20\, cm$, using a bimetallic strip made of brass and iron each of different length The length of both components would change in such a way that difference between their lengths remains constant If length of brass is $40 \,cm$ and length of iron will be ________$cm$\((\alpha_{iron}=1.2\times10^{-5}K^{-1} \,\,\,and \,\,\,\alpha_{brass}=1.8\times10^{-5}K^{-1}).\)

In a Carnot engine, if the temperatures of the source and sink are both decreased by 100 K, the efficiency:
A 50 g ice cube at -10°C is added to 200 g of water at 30°C. The final temperature of the mixture is: (Specific heat of water = 1 cal g\(^{-1}\)°C\(^{-1}\), latent heat of fusion of ice = 80 cal g\(^{-1}\), specific heat of ice = 0.5 cal g\(^{-1}\)°C\(^{-1}\))
For a system undergoing isothermal process, heat energy is supplied to the system. Choose the option showing correct statements
(a) Internal energy will increase
(b) Internal energy will decrease
(c) Work done by system is positive
(d) Work done by system is negative
(e) Internal energy remains constant
A diatomic gas has an initial internal energy of 80 cal. A work of 18 cal is done on the gas, and the gas releases heat energy of 42 J. The final internal energy of the gas is:
Three moles of a gas at a temperature \( T \) are heated to thrice its volume by keeping the pressure constant. If \( \gamma \) is the ratio of specific heats, then the increase in internal energy of the gas is:
The relation between volume (V) and absolute temperature (T) of a gas in an adiabatic process is:
The relation between absolute temperature (T) and pressure (P) in adiabatic process is:

A thermodynamic system is taken from an original state D to an intermediate state E by the linear process shown in the figure. Its volume is then reduced to the original volume from E to F by an isobaric process. The total work done by the gas from D to E to F will be

A thermodynamic system is taken from an original state D to an intermediate state

The correct option for free expansion of an ideal gas under adiabatic condition is :
A sample of 0.1 g of water at 100°C and normal pressure (1.013 × 105 Nm-2 ) requires 54 cal of heat energy to convert to steam at 100°C. If the volume of the steam produced is 167.1 cc, the change in internal energy of the sample, is
$2$ moles of an ideal monatomic gas is carried from a state $(P_0, V_0)$ to a state $(2P_0, 2V_0)$ along a straight line path in a P-V diagram. The amount of heat absorbed by the gas in the process is given by
During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its temperature. The ratio of Cp/Cv for the gas is
The latent heat of fusion of ice at $0^{\circ} C$ is $80\, cal / g$. Entropy change $(\Delta S)$ accompanying the melting of $1\, g$ of ice at $0^{\circ} C$ would be (units: $cal / g / K$ )
We consider a thermodynamic system. If $ \Delta U $ represents the increase in its internal energy and $ W $ the work done by the system, which of the following statements is true ?
The absolute enthalpy of neutralisation of the reaction $MgO (s)+2 HCl (a q) \longrightarrow MgCl _{2}(a q)+ H _{2} O (l)$ will be
A black body at $200\, K$ is found to exit maximum energy at a wavelength $14\, \mu\, m$ When its temperature is raised to $1000\, K$, then wavelength at which maximum energy emitted is
The molar heat capacity of water at constant pressure, $C$, is $75\, JK ^{-1}\, mol ^{-1}$. When $1.0\, KJ$ of heat is supplied to $100\, g$ of water which is free to expand, the increase in temperature of water is :
For a gas undergoing an adiabatic process, the relation between temperature and volume is found to be $ T{{V}^{0.4}}= $ constant. This gas must be:
Starting with the same initial conditions, an ideal gas expands from volume V$_1$ to V$_2$ in three different ways, the work done by the gas is W$_1$ if the process is purely isothermal, W$_2$ if purely isobaric and W$_3$ if purely adiabatic, then
If the temperature of a black body increased rom $ 27{}^\circ C $ to $ 327{}^\circ C $ , the radiation emitted increases by a fraction of: