Carnot efficiency depends on: MCQ with Answer and Explanation

Carnot efficiency depends on:
A. Both (a) and (b)
B. Working substance
C. Engine size
D. Source and sink temperatures only
Answer: Option D
Solution (By JKExamLibrary)
η = 1 - T₂/T₁: depends only on absolute temperatures, independent of working fluid or design. Universal maximum efficiency limit. Memory tip: 'Carnot: only T_hot and T_cold matter; real engines less efficient'. Thermodynamics concept frequently tested in competitive exams.

This question belongs to: Science Physics

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Physics Questions

Question #1 Report Error
The core of a transformer is laminated to reduce
A. Hysteresis loss
B. Copper loss
C. Flux leakage
D. Eddy current loss

Correct Answer: Option D


Explanation:
Lamination of core increases resistance to circulating eddy currents, reducing eddy current losses (I²R). Hysteresis loss reduced by using soft iron. Copper loss is in windings. Lamination is insulation between layers.

This question belongs to: Science Physics
Question #2 Report Error
A freely falling body exhibits which type of motion?
A. Uniform velocity
B. Non-uniform acceleration
C. Uniform acceleration
D. Zero acceleration

Correct Answer: Option C


Explanation:
A freely falling body falls under the sole influence of Earth's gravity (neglecting air resistance). Near the surface of the Earth, the acceleration due to gravity ('g') is constant (approximately 9.8 m/s²). Because the acceleration does not change during the fall, it is an example of uniform accelerated motion.

This question belongs to: Science Physics
Question #3 Report Error
In a pressure cooker, food cooks faster because:
A. Material conducts heat better
B. Boiling point of water increases due to high pressure
C. Steam circulates rapidly
D. Heat is trapped inside

Correct Answer: Option B


Explanation:
Pressure cooker seals steam, increasing internal pressure above atmospheric. Higher pressure raises water's boiling point (above 100°C), allowing food to cook at higher temperature, speeding up chemical reactions. Option A is vague; C and D are secondary effects. Memory tip: 'Higher pressure ⇒ higher boiling point ⇒ faster cooking'. This daily-life physics question tests application of pressure-temperature relationship in liquids, frequently appearing in competitive exams. Always recall that phase change temperatures depend on pressure (e.g., water boils below 100°C on mountains).

This question belongs to: Science Physics