A Carnot engine, having an efficiency of η=1/10 as heat engine, is used

⇦

⇨

A Carnot engine, having an efficiency of η=1/10 as heat engine, is used as a refrigerator. If the work done on the system is 10J, the amount of energy absorbed from the reservoir at lower temperature is

Options

(a) 100 J
(b) 99 J
(c) 90 J
(d) 1 J

Correct Answer:

90 J

Explanation:

Efficiency of carnot engine n = 1 – (T₂ / T₁)
That is, 1 / 10 = 1 – (T₂ / T₁)
⇒ (T₂ / T₁) = 1 – (1 / 10) = 9 / 10 ⇒ (T₁ / T₂) = 10 / 9
.·. w = Q₂ . [(T₁ / T₂) – 1) ⇒ 10 = Q₂ [(10 / 9) – 1]
⇒ 10 = Q₂ (1 / 9) ⇒ Q₂ = 90 J
So, 90 J heat is absorbed at lower temperature.

Related Questions:

1. Photons of energy 6 eV are incident on a metal surface whose work function is 4 eV.
2. If alpha, beta and gamma rays carry same momentum, which has the longest
3. When a mass M is attached to the spring of force constant k,
4. The magnetic field in a certain region of space is given by B =8.35×10⁻² Î T.
5. The ferromagnetic substance is

Topics: Thermodynamics (179)
Subject: Physics (2479)

---

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

---

Share this page with your friends