As stated by the first law of thermodynamics__________________?
Show answer Hide answer
Answer: D. total energy of a system remains constant
Explanation
The first law of thermodynamics is the fundamental principle of energy conservation. It establishes that energy can be transformed between forms but never created nor destroyed. Total energy within an isolated system remains constant regardless of internal thermodynamic processes. Thermodynamics studies the relationships between heat, work, temperature, and energy transfer. Energy conservation applies universally across mechanical, electrical, and thermal engineering systems. Closed systems account for energy crossing boundaries as heat and work interactions.
Power plant design relies on the first law to balance energy inputs from fuel with electrical outputs. Thermal efficiency calculations track energy transformations to minimize waste in industrial processes. Understanding energy conservation is essential for developing sustainable renewable energy technologies. Option A incorrectly limits the law to heat and work equivalence without generalized energy conservation. Option B is too narrow because internal energy alone can change if heat or work crosses boundaries. Option C is false because entropy increases in irreversible processes and is not conserved.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. According to Avogadro’s law, under constant pressure and temperature, every gas molecule has_________________?
Show answer Hide answer
Answer: E. occupies same volume
Avogadro's law states that equal volumes of gases at identical conditions contain equal molecules. Consequently, every gas molecule occupies the exact same volume per mole under constant pressure. This fundamental gas la...
Q2. What principle is established by the first law of thermodynamics_______________________?
Show answer Hide answer
Answer: C. heat and work are mutually convertible
The first law of thermodynamics is a statement of the conservation of energy principle. It proves that heat and work are mutually convertible forms of thermal energy transfer. Energy cannot be created or destroyed, only...
Q3. What is a thermodynamic heat exchange process called when the product of pressure and volume stays constant_______________?
Show answer Hide answer
Answer: E. hyperbolic process
An isothermal process for an ideal gas where pressure multiplied by volume remains constant forms a hyperbola. Boyle law proves that pressure and volume are inversely proportional at constant temperature, yielding hyperb...
Q4. The Scott-Russell mechanism is composed of_________________?
Show answer Hide answer
Answer: A. sliding and turning pairs
The Scott-Russell mechanism utilizes both sliding pairs and turning pairs to function. This combination allows the linkage to convert rotary motion into exact linear motion. Sliding blocks move along straight guides whil...
Q5. The kinematic pair formed by two elements connected such that one is constrained to revolve about a fixed axis of the other is referred to as__________________?
Show answer Hide answer
Answer: A. turning pair
A turning pair constrains one kinematic element to revolve around a fixed axis of another. This revolute joint permits only rotational relative motion while preventing linear translation. Pin joints and hinge connections...
Q6. Absolute zero pressure takes place _____________________?
Show answer Hide answer
Answer: C. when molecular momentum of the system becomes zero
Pressure in a gas is caused by molecular collisions against container walls transferring momentum. When temperature drops to absolute zero, molecular thermal motion and associated momentum completely cease. Without any m...