1
COMEDK 2025 Evening Shift
MCQ (Single Correct Answer)
+1
-0
A given volume of gas at NTP is allowed to expand 6 times of its original volume, first under isothermal condition and then under adiabatic condition. Which of the given statement is correct? [Given $\frac{c_p}{c_v}=\gamma=1.4$ ]
A
The final pressure after the adiabatic expansion is 1.4 times greater than the final pressure after the isothermal expansion.
B
The final temperature after the adiabatic expansion is 1.4 times less than the final temperature after the isothermal expansion.
C
Pressure remains same in both adiabatic and isothermal expansion
D
The final pressure after the adiabatic expansion is less than the final pressure after the isothermal expansion.
2
COMEDK 2025 Evening Shift
MCQ (Single Correct Answer)
+1
-0
The rate of heat conduction in the given two metal rods having the same length is found to be the same when the temperature difference between the ends is kept $30^{\circ} \mathrm{C}$ If the area of cross section of the first rod is $8 \times 10^{-2} \mathrm{~m}^2$ then what will be area of cross section of the second rod? [ Given that the ratio of the thermal conductivity of the first rod to that of the second rod is $1: 4$ ]
A
$2 \times 10^{-2} \mathrm{~m}^2$
B
$4 \times 10^{-4} \mathrm{~m}^2$
C
$2 \times 10^{-4} \mathrm{~m}^2$
D
$4 \times 10^{-2} \mathrm{~m}^2$
3
COMEDK 2025 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0
The heat required to increase the temperature of 4 moles of a mono-atomic ideal gas from $273^{\circ} \mathrm{C}$ to $473^{\circ} \mathrm{C}$ at constant volume is
A
1600 R
B
600 R
C
1200 R
D
400 R
4
COMEDK 2025 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0
Rods $A$ and $B$ have their lengths in the ratio $1: 2$. Their thermal conductivities are $K_1$ and $K_2$ respectively. The temperatures at the ends of each rod are $\mathrm{T}_1$ and $\mathrm{T}_2$. If the rate of flow of heat through the rods is equal, the ratio of area of cross section of $A$ to that of $B$ is
A
$\frac{2 K_2}{K_1}$
B
$\frac{K_2}{4 K_1}$
C
$\frac{K_2}{K_1}$
D
$\frac{K_2}{2 K_1}$
COMEDK Subjects
EXAM MAP