Heat and Thermodynamics PYQs - Last 5 Years
AP EAPCET / Physics / Mechanics / 138 recent questions
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Practice 138 AP EAPCET Physics questions from Heat and Thermodynamics. Use the year-wise and type-wise breakdown to prioritize recent PYQs, then continue into the question list below.
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Last 5 Years Heat and Thermodynamics Questions
Showing 50 of 138 filtered questions.
1Heat And Thermodynamics
If the ratio of the absolute temperature of the sink and source of a Carnot engine is changed from $2: 3$ to $3: 4$, the efficiency of the engine change by
MCQ+1 / -02024
2Heat And Thermodynamics
When 2 moles of a monoatomic gas expands adiabatically from a temperature of $80^{\circ} \mathrm{C}$ to $50^{\circ} \mathrm{C}$, the work done is $W$. The work done when 3 moles of a diatomic gas expands adiabatically from $50^{\circ} \math...
MCQ+1 / -02024
3Heat And Thermodynamics
An ideal gas is taken around $A B C A$ as shown in the $P^{\prime \prime}$ diagram. The work done during the cycle is
MCQ+1 / -02024
4Heat And Thermodynamics
The ratio of kinetic energy of a diatomic gas molecule at a high temperature to that of NTP is
MCQ+1 / -02024
5Heat And Thermodynamics
Initially the pressure of 1 mole of an ideal gas is $10^5 \mathrm{Nm}^{-2}$ and its volume is 16 L . When it is adiabatically compressed, its final volume is 2 L . Work-done on the gas is $\left[\right.$ molar specific heat at constant volu...
MCQ+1 / -02024
6Heat And Thermodynamics
The efficiency of a heat engine that works between the temperatures where Celsius-Fahrenheit scales coincides and Kelvin-Fahrenheit scales coincides is (approximately)
MCQ+1 / -02024
7Heat And Thermodynamics
A metal ball of mass 100 g at $20^{\circ} \mathrm{C}$ is dropped in 200 g of water at $80^{\circ} \mathrm{C}$. If the resultant temperature is $70^{\circ} \mathrm{C}$, then the ratio of specific heat of the metal to that of water is
MCQ+1 / -02024
8Heat And Thermodynamics
The total internal energy of 2 moles of a monoatomic gas at a temperature $27^{\circ} \mathrm{C}$ is $U$. The total internal energy of 3 moles of a diatomic gas at a temperature $127^{\circ} \mathrm{C}$ is
MCQ+1 / -02024
9Heat And Thermodynamics
When 80 J of heat is absorbed by a monoatomic gas, its volume increases by $16 \times 10^{-5} \mathrm{~m}^3$. The pressure of the gas is
MCQ+1 / -02024
10Heat And Thermodynamics
Water of mass $m$ at $30^{\circ} \mathrm{C}$ is mixed with with 5 g of ice at $-20^{\circ} \mathrm{C}$. If the resultant temperature of the mixture is $6^{\circ} \mathrm{C}$, then the value of $m$ is (specific heat capacity of ice $=0.5 \ma...
MCQ+1 / -02024
11Heat And Thermodynamics
The efficiency of a Carnot heat engine is $25 \%$ and the temperature of its source is $127^{\circ} \mathrm{C}$. Without changing the temperature of the source, if absolute temperature of the sink is decreased by $10 \%$, the efficiency of ...
MCQ+1 / -02024
12Heat And Thermodynamics
Two ideal gases $A$ and $B$ of same number of moles expand at constant temperatures $T_1$ and $T_2$ respectively such that the pressure of gas $A$ decreases by $50 \%$ and the pressure of gas $B$ decreases by $75 \%$. If the work done by bo...
MCQ+1 / -02024
13Heat And Thermodynamics
Heat energy absorbed by a system going through the cyclic process shown in the figure is
MCQ+1 / -02024
14Heat And Thermodynamics
A polyatomic gas with $n$ degrees of freedom has a mean kinetic energy per molecule given by (if $N$ is Avogadro's number )
MCQ+1 / -02024
15Heat And Thermodynamics
In a Carnot engine, when the temperatures are $T_2=0^{\circ} \mathrm{C}$ and $T_1=200^{\circ} \mathrm{C}$, its efficiency is $\eta_1$ and when the temperature are $T_1=0^{\circ} \mathrm{C}$ and $T_2=-200^{\circ} \mathrm{C}$, its efficiency...
MCQ+1 / -02024
16Heat And Thermodynamics
A monoatomic gas of $n$ moles is heated from temperature $T_1$ to $T_2$ under two different conditions, (i) at constant volume and (ii) at constant pressure. The change in internal energy of the gas is
MCQ+1 / -02024
17Heat And Thermodynamics
A slab consists of two identical plates of copper and brass. The free face of the brass is at $0^{\circ} \mathrm{C}$ and that of copper at $100^{\circ} \mathrm{C}$. If the thermal conductivities of brass and copper are in the ratio $1: 4$,...
MCQ+1 / -02024
18Heat And Thermodynamics
An ideal gas is found to obey $p V^{\frac{3}{2}}=$ constant during an adiabatic process. If such a gas initially at temperature $T$ is adiabatically compressed to $\frac{1}{4}$ th of its volume, then its final temperature is
MCQ+1 / -02024
19Heat And Thermodynamics
A metal block is made from mixture of 2.4 kg of aluminium, 1.6 kg of brass and 0.8 kg of copper. The metal block is initially at $20^{\circ} \mathrm{C}$. If the heat supplied to the metal block is 44.4 cal . Find the final temperature of th...
MCQ+1 / -02024
20Heat And Thermodynamics
Match the following ( $f$ is number of degrees of freedom)
$$
\begin{array}{llll}
\hline& \text { Gases } & & \frac{C_p}{C_v} \text { value } \\
\hline \text { A } & \text { Monoatomic } & \text { I } & \frac{4+f}{3+f} \\
\hline \text { B ...
$$
\begin{array}{llll}
\hline& \text { Gases } & & \frac{C_p}{C_v} \text { value } \\
\hline \text { A } & \text { Monoatomic } & \text { I } & \frac{4+f}{3+f} \\
\hline \text { B ...
MCQ+1 / -02024
21Heat And Thermodynamics
The efficiency of a Carnot engine found to increase from $25 \%$ to $40 \%$ on increasing the temperature ( $T_1$ ) of source alone through 100 K . The temperature $\left(T_2\right)$ of the sink is given by
MCQ+1 / -02024
22Heat And Thermodynamics
The condition $d W=d Q$ holds good in the following process.
MCQ+1 / -02024
23Heat And Thermodynamics
When the temperature of a gas is raised from $27^{\circ} \mathrm{C}$ to $90^{\circ} \mathrm{C}$. The increase in the rms velocity of the gas molecule is
MCQ+1 / -02024
24Heat And Thermodynamics
A Carnot engine has the same efficiency between 800 K and 500 K and $x>600 \mathrm{~K}$ and 600 K . The value of $x$ is
MCQ+1 / -02024
25Heat And Thermodynamics
The efficiency of Carnot cycle is $\frac{1}{6}$. By lowering the temperature of sink by 65 K , it increases to $\frac{1}{3}$. The initial and final temperature of the sink are
MCQ+1 / -02024
26Heat And Thermodynamics
In a cold storage ice melts at the rate of 2 kg per hour when the external temperature is $20^{\circ} \mathrm{C}$. The minimum power output of the motor used to drive the refrigerator which just prevents the ice from melting is (latent heat...
MCQ+1 / -02024
27Heat And Thermodynamics
The temperature difference across two cylindrical rods $A$ and $B$ of same material and same mass are $40^{\circ} \mathrm{C}$ and $60^{\circ} \mathrm{C}$ respectively. In steady state, if the rates of flow of heat through the rods $A$ and $...
MCQ+1 / -02024
28Heat And Thermodynamics
When 100 J of heat is supplied to a gas, the increase in the internal energy of the gas is 60 J . Then the gas is /can
MCQ+1 / -02024
29Heat And Thermodynamics
The absorption coefficient value of a perfect black body is
MCQ+1 / -02024
30Heat And Thermodynamics
The efficiency of a Carnot's engine is $25 \%$. When the temperature of sink is 300 K . The increase in the temperature of source required for the efficiency to become $50 \%$ is
MCQ+1 / -02024
31Heat And Thermodynamics
A certain volume of a gas at 300 K expands adiabatically until its volume is doubled. The resultant fall in temperature of the gas is nearly (The ratio of the specific heats of the gas $=1.5$ )
MCQ+1 / -02024
32Heat And Thermodynamics
An ideal gas is kept in a cylinder of volume $3 \mathrm{~m}^3$ at a pressure of $3 \times 10^5 \mathrm{~Pa}$. The energy of the gas is
MCQ+1 / -02024
33Heat And Thermodynamics
The rms velocity of a gas molecules oí mass $m$ at a given temperature is proportional to
MCQ+1 / -02024
34Heat And Thermodynamics
A Carnot heat engine has an efficiency of $10 \%$. If the same engine is worked backward to obtain a refrigerator, then the coefficient of performance of the refrigerator is
MCQ+1 / -02024
35Heat And Thermodynamics
If ambient temperature is 300 K , the rate of cooling at 600 K is $H$. In the same surroundings, the rate of cooling at 900 K is
MCQ+1 / -02024
36Heat And Thermodynamics
An ideal heat engine operates in Carnot cycle between $127^{\circ} \mathrm{C}$ and $27^{\circ} \mathrm{C}$. It absorbs $5 \times 10^4 \mathrm{Cal}$ of heat at height temperature. Amount of heat converted to work is
MCQ+1 / -02024
37Heat And Thermodynamics
One mole of a gas having $\gamma=\frac{7}{5}$ is mixed with one mole of a gas having $\gamma=\frac{4}{3}$. The value of $\gamma$ for the mixture is ( $\gamma$ is the ratio of the specific heats of the gas)
MCQ+1 / -02024
38Heat And Thermodynamics
The molar specific heat capacity of a diatomic gas at constant pressure is $C$. The molar specific heat capadtr of a monoatomic gas at constant volume is
MCQ+1 / -02024
39Heat And Thermodynamics
In a Carnot engine, the absolute temperature of the source is $25 \%$ more than the absolute temperature of the sink. The efficiency of the engine is
MCQ+1 / -02024
40Heat And Thermodynamics
When 403 of heat is absorbed by a monoatomic gas the increase in the internal energy of the gas is
MCQ+1 / -02024
41Heat And Thermodynamics
The work done by an ideal gas of 2 moles in increasins its volume from $V$ to 2 V at constant temperature $T$ is V . The work done by an ideal gas of 4 moles in increasits its wolume from $V$ to $8 V$ at constant temperature $\frac{T}{2}$ i...
MCQ+1 / -02024
42Heat And Thermodynamics
The length of a metal bar is 20 cm and the ares of cross-section is $4 \times 10^{-4} \mathrm{~m}^2$. If one end of the rod is kept in ice at $0^{\circ} \mathrm{C}$ and the other end is kept in steamat $100^{\circ} \mathrm{C}$, the mass of ...
MCQ+1 / -02024
43Heat And Thermodynamics
Match the following. .tg {border-collapse:collapse;border-spacing:0;} .tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; overflow:hidden;padding:10px 5px;word-break:normal;} .tg th...
MCQ+1 / -02024
44Heat And Thermodynamics
The specific heat capacity of a copper block of mass $M$ is $s$. If the mass of the copper block is doubled, the specific heat capacity will be
MCQ+1 / -02023
45Heat And Thermodynamics
Isothermal bulk modulus of a gas at a pressure $p$ is ( $\gamma$-ratio of specific heat capacities of the gas)
MCQ+1 / -02023
46Heat And Thermodynamics
A block of steel of mass 2 kg slides down a rough inclined plane of inclination of $\sin ^{-1}\left(\frac{3}{5}\right)$ at a constant speed. The temperature of the block as it slides through 80 cm , assuming that the mechanical energy lost ...
MCQ+1 / -02023
47Heat And Thermodynamics
A vessel of volume 10 litres is filled with $\mathrm{H}_2$ gas. The total average translational kinetic energy of its molecules is $4.5 \times 10^5 \mathrm{~J}$. The pressure of hydrogen in the vessel is
MCQ+1 / -02023
48Heat And Thermodynamics
2 moles of a monatomic gas requires heat energy $Q$ to be heated from $30^{\circ} \mathrm{C}$ to $40^{\circ} \mathrm{C}$ at constant volume. The heat energy required to raise the temperature of 4 moles of a diatomic gas from $28^{\circ} \ma...
MCQ+1 / -02023
49Heat And Thermodynamics
A monatomic gas of volume $V$ and pressure $p$ expands isothermally to a volume $27 V$ and then compressed adiabatically to a volume $V$. The final pressure of the gas is
MCQ+1 / -02023
50Heat And Thermodynamics
The specific heat capacity of a monatomic gas at constant volume is $x \%$ of its specific heat capacity at constant pressure. Then, $x=$
MCQ+1 / -02023
