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. An aeroplane flies 400m due to North and then 300m due to south and then flies
2. The induced emf in a coil of 10 H inductance in which current varies
3. When the energy of the incident radiation is increased by 20%,
4. The angle between the dipole moment and electric field at any point on the equatoria
5. The wavelength of light emitted from second orbit to first orbit in a hydrogen atom 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