Question 1 :
The internal energy of a solid also increases when the heat is transferred to its surroundings. A 5 kg solid bar is heated at atmospheric pressure. Its temperature increases from $20^{0}C$ to $70^{0}C$. The linear expansion coefficient of solid bar is $ 1 \times 10^{-3}/C^{0}$. The density of a solid bar is 50 kg/$m^{3}$. The specific heat capacity of a solid bar is 200 J/kg C$^{0}$. The atmospheric pressure is $ 1 \times 10^{5} N/m^{2}$.<br/> The work done by the solid bar due to thermal expansion, under atmospheric pressure, is

Question 2 :
A steel drill is making $180$ Revolutions per minute, under a constant torque of $5 N-m$. If it drills a hole in $7 s$. in a steel block of mass $600 gm$, rise in temperature of the block is $(s= 0.1 cal/gm/ $ <br> ${^ \circ} C$)<br/>

Question 3 :
${ 0.1\ m }^{ 3 }$ of water at ${ 80 }^{ \circ }C$ is mixed with ${ 0.3\ m }^{ 3 }$ of water at ${ 60 }^{ \circ }C$. The final temperature of the mixture is<br/>

Question 4 :
Assertion: Fahrenheit is the smallest unit measuring temperature. Reason: Fahrenheit was the first temperature scale used for measuring temperature.

Question 6 :
Air in a cylinder is suddenly compressed by a piston, which is then maintained at the same position. With the passage of time :<br/>

Question 7 :
In a process, 20 joules of heat is added to an ideal gas and the gas does 12 joules of work. Which of the following is true about the internal energy of the gas during this process?

Question 8 :
If a system undergoes contraction of volume then the work done by the system will be

Question 9 :
If heat is supplied to an ideal gas in an isothermal process,

Question 10 :
For an ideal gas equation of a process for which the heat capacity of the gas varies with temperature as C = $\dfrac { \alpha }{ T }$ ($\alpha$ is a constant) is given by

Question 11 :
In changing the state of thermodynamics from A to B state, the heat required is Q and the work done by the system is W. The change in its internal energy is

Question 12 :
Assertion: Between two thermodynamic states, the value of $(Q - W)$ is constant for any process. Reason: $Q$ and $W$ are path functions.

Question 13 :
In a cyclic process, the change in the internal energy of a system over one complete cycle

Question 14 :
A cylinder with fixed capacity of $67.2$ lit contains helium gas at STP. The amount of heat needed to raise the temperature of the gas by $20^0C$ is :

Question 15 :
Internal energy of $ n_{1} $ mol of hydrogen of temperature $ T $ is equal to the internal energy of $ n_{2} $ mol of helium at temperature $ 2 T . $ The ratio $\dfrac{ n_{1} }{ n_{2}} $ is

Question 16 :
The amount of work, which can be obtained by supplying 200 cal of heat, is

Question 17 :
Which of the following is an example of the first law of thermodynamics ?

Question 18 :
Heat of $20\ Kcal$ is supplied to the system and $8400\ J$ of external work is done on the system so that its volume decreases at constant pressure. The change in internal energy is ($J=4200\ J/kcal$)

Question 19 :
The specific heat of hydrogen gas at constant pressure is $C_{p} = 3.4 \times 10^{3} cal / kg ^{o}C$ and at constant volume is $C_{V} = 2.4 \times 10^{3} cal / kg ^{o}C$ If one kilogram hydrogen gas is heated from $10^{o} C$ to $ 20^{o} C$ at constant pressure, the external work done on the gas to maintain is at constant pressure is

Question 20 :
The first law of thermodynamics is concerned with the conservation of

Question 22 :
A system perform work $\bigtriangleup W$ when an amount of heat $\bigtriangleup Q$ added to the system the corresponding change in the internal energy is $\bigtriangleup U$. A unique function of the intial and final states (irrespective of the mode of change ) is

Question 23 :
A container is filled with 20 moles of an ideal diatomic gas at absolute temperature T. When heat is supplied to gas temperature remains constant but 8 moles dissociate into atoms. Heat energy given to gas is

Question 24 :
5 mole of helium are mixed with 2 mole of hydrogen to form a mixture. Take molar mass of helium $M_1=4 g$ and that of Hydrogen $M_2=2 g$ <br>If the internal energy of He sample of 100 J and that of the hydrogen sample is 200 J, then the internal energy of the mixture is:

Question 25 :
A gas is compressed at constant pressure $ 50 N/m^2$ from a volume of $ 0m^3$ to a volume $ 4m^3 . $ Energy $100 J$ is then added to the gas by heating. Its internal energy is :

Question 26 :
STATEMENT-1: There is a natural asymmetry between converting work to heat and converting heat to work.<br/><br/>STATEMENT-2: No process is possible in which the sole result is the absorption of heat from a reservoir and its complete conversion into work.

Question 27 :
In a thermodynamic process pressure of a fixed mass of a gas is changed in such a manner that the gas releases $20J$ of heat and $8J$ of work is done on the gas. If initial internal energy of the gas was $30J$, what will be the fixed internal energy?

Question 28 :
Find the external work done by the system inkcal, when 20 keal of heat is supplied to thesystem and the increase in the internal energy is 8400$\mathrm { J } ( \mathrm { J } = 4200 \mathrm { J } / \mathrm { kcal } ) ?$

Question 29 :
An iron block of mass $2\;kg$, falls from a height of $10m$. After colliding with the ground it loses $25\%$ energy to surroundings and rest is gained as heat. Then find the temperature rise of the block. (Take sp. heat of iron $470\;J/kg^{\circ}C$)<br/>

Question 30 :
Two identical containers $ A $ and $ B $ have frictionless pistons. They contain the same volume of an ideal gas at the same temperature. The mass of the gas in $ A $ is $ m_{A} $ and that in $ B $ is $ m_{B} $. The gas in each cylinder is now allowed to expand isothermally to double the initial volume. The change in the pressure in $ A $ and $ B $, respectively, is $ \Delta p $ and $ 1.5 \Delta p $ Then