Question:
A gas absorbs 500 J heat and does 200 J work. Change in internal energy is:
A gas absorbs 500 J heat and does 200 J work. Change in internal energy is:
Show Hint
Think of it like a bank account: 500 J is "deposited" (heat absorbed), and 200 J is "spent" (work done). The balance remaining in the account is the change in internal energy (300 J).
Updated On: Jun 3, 2026
- 300 J
- 500 J
- 700 J
- -300 J
Show Solution
Verified By Collegedunia
The Correct Option is A
Solution and Explanation
Concept:
This problem is based on theFirst Law of Thermodynamics**, which is a statement of the law of conservation of energy. It relates the heat supplied to a system, the work done by the system, and the change in its internal energy.
• Formula: \( \Delta U = Q - W \)
• \( \Delta U \): Change in internal energy.
• \( Q \): Heat added to the system (Positive if absorbed, Negative if released).
• \( W \): Work done by the system (Positive if work is done by gas, Negative if work is done on gas).
Step 1: Identifying the given values with sign conventions.
Heat absorbed by the gas (\( Q \)) = +500 J (since energy is entering the system).
Work done by the gas (\( W \)) = +200 J (since the system is doing the work on surroundings).
Step 2: Applying the First Law of Thermodynamics.
Substitute the values into the formula: \[ \Delta U = Q - W \] \[ \Delta U = 500 \text{ J} - 200 \text{ J} \] \[ \Delta U = 300 \text{ J} \]
Step 3: Conclusion.
The internal energy of the gas increases by 300 J. This energy is stored within the gas, typically manifesting as an increase in temperature.
• Formula: \( \Delta U = Q - W \)
• \( \Delta U \): Change in internal energy.
• \( Q \): Heat added to the system (Positive if absorbed, Negative if released).
• \( W \): Work done by the system (Positive if work is done by gas, Negative if work is done on gas).
Step 1: Identifying the given values with sign conventions.
Heat absorbed by the gas (\( Q \)) = +500 J (since energy is entering the system).
Work done by the gas (\( W \)) = +200 J (since the system is doing the work on surroundings).
Step 2: Applying the First Law of Thermodynamics.
Substitute the values into the formula: \[ \Delta U = Q - W \] \[ \Delta U = 500 \text{ J} - 200 \text{ J} \] \[ \Delta U = 300 \text{ J} \]
Step 3: Conclusion.
The internal energy of the gas increases by 300 J. This energy is stored within the gas, typically manifesting as an increase in temperature.
Was this answer helpful?
0
0
Top AP EAPCET Physics Questions
- A body is projected from the ground at an angle of $\tan^{-1} \left( \frac{8}{7}\right)$ with the horizontal. The ratio of the maximum height attained by it to its range is
- A lens forms real and virtual images of an object, when the object is at $u_{1}$ and $u_{2}$ distances respectively. If the size of the virtual image is double that of the real image, then the focal length of the lens is (take, the magnification of the real image as $m$ )
- Two spheres $P$ and $Q$, each of mass $200\, g$ are attached to a string of length one metre as shown in the figure. The string and the spheres are then whirled in a horizontal circle about $O$ at a constant angular speed. The ratio of the tension in the string between $P$ and $Q$ to that of between $P$ and $O$ is $(P$ is at mid-point of the line joining $O$ and $Q$ )
- The radii of the two columns in a U - tube are r1 and r2. When a liquid of density p (angle of contact is $ 0{}^\circ $ ) is filled in it, the level difference of the liquid in the two arms is h. The surface tension of the liquid is: (g = acceleration due to gravity)
- A rigid metallic sphere is spinning around its own axis in the absence of external torque. If the temperature is raised, its volume increases by $9 \%$. The change in its angular speed is
View More Questions
Top AP EAPCET Thermodynamics Questions
- A solid sphere at a temperature of 400 K radiates a power $P$. If the radius of the sphere is halved and its absolute temperature is doubled, then the power radiated by it is
- When a polyatomic gas is heated at constant pressure, the percentage of heat given to the gas that is converted into external work is
(Ratio of the specific heat capacities of the gas = $\frac{4}{3}$) - The thermodynamic process in which the change in internal energy of the system becomes zero is
- The efficiency of a Carnot engine operating between the temperatures 1000 K and 300 K is
- A closed vessel contains a gas at a pressure $P$. If 50% of the mass of the gas is removed and rms speed of the gas molecules is increased by 20%, then the pressure of the remaining gas is
View More Questions
Top AP EAPCET Questions
- A body is projected from the ground at an angle of $\tan^{-1} \left( \frac{8}{7}\right)$ with the horizontal. The ratio of the maximum height attained by it to its range is
- The four quantum numbers of the valence electron of potassium are :
- A lens forms real and virtual images of an object, when the object is at $u_{1}$ and $u_{2}$ distances respectively. If the size of the virtual image is double that of the real image, then the focal length of the lens is (take, the magnification of the real image as $m$ )
- Two spheres $P$ and $Q$, each of mass $200\, g$ are attached to a string of length one metre as shown in the figure. The string and the spheres are then whirled in a horizontal circle about $O$ at a constant angular speed. The ratio of the tension in the string between $P$ and $Q$ to that of between $P$ and $O$ is $(P$ is at mid-point of the line joining $O$ and $Q$ )
- The volume of $0.02\, M$ acidified permanganate solution required for complete reaction of $60\, mL$ of $0.01\, MI^{-}$ ion solution to form $I_2$ in $mL$ is
View More Questions