Heat and Mass Transfer Objective Questions with Answers – Set 09

Its our pleasure to assist you towards your goal. for inbuilt quality question with standard solution may help you a lot. you guys are looking for Mechanical engineering MCQ question with answers PDF free download as per Mechanical engineering new exam pattern? you come for the right page. Each question has four option followed by the right answer. these Mechanical MCQ question and solution may help you to get better performance in exam .

All questions answers in the last paragraph

Q1. The critical thickness of insulation for a sphere is

(A) k/h₀
(B) 2k/h₀
(C) h₀/k
(D) h₀/2k

Q2. The transfer of heat by molecular collision is known as

(A) Conduction
(B) Convection
(C) Radiation
(D) None of these

Q3. The process of heat transfer from one particle of the body to another by the actual motion of the heated particles, is called

(A) Conduction
(B) Convection
(C) Radiation
(D) None of these

Q4. Thermal conductivity of water in general with rise in temperature

(A) Increases
(B) Decreases
(C) Remain constant
(D) May increase or decrease depending on temperature

Q5. LMTD in case of counter flow heat exchanger as compared to parallel flow heat exchanger is

(A) Higher
(B) Lower
(C) Same
(D) Depends on the area of heat exchanger

Q6. The amount of radiation mainly depends on

(A) Nature of body
(B) Temperature of body
(C) Type of surface of body
(D) All of the above

Q7. Fourier’s law of heat conduction is valid for

(A) One dimensional cases only
(B) Two dimensional cases only
(C) Three dimensional cases only
(D) Regular surfaces having non-uniform temperature gradients

Q8. Which of the following property of air does not increase with rise in temperature?

(A) Thermal conductivity
(B) Thermal diffusivity
(C) Density
(D) Dynamic viscosity

Q9. Depending on the radiating properties, a body will be white when
(Where a = absorptivity, p = reflectivity, x = transmissivity)

(A) P = 0, x = 0 and a = 1
(B) P=1, T = 0 and a = 0
(C) P = 0, x = 1 and a = 0
(D) X = 0, a + p = 1

Q10. The emissivity for a black body is

(A) 0
(B) 0.5
(C) 0.75
(D) 1

Q11. The transfer of heat by molecular collision is smallest in

(A) Solids
(B) Liquids
(C) Gases
(D) None of these

Q12. 40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is

(A) 0.45
(B) 0.55
(C) 0.40
(D) 0.75

Q13. Kirchhoff’s law states that

(A) The total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature
(B) The wave length corresponding to the maximum energy is proportional to the absolute temperature
(C) The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body
(D) None of the above

Q14. The expression Q = ρ AT4 is called

(A) Fourier equation
(B) Stefan-Boltzmann equation
(C) Newton Reichmann equation
(D) Joseph-Stefan equation

Q15. A steam pipe is to be lined with two layers of insulating materials of different thermal conductivities. For the minimum heat transfer,

(A) The better insulation must be put inside
(B) The better insulation must be put outside
(C) One could place either insulation on either side
(D) One should take into account the steam temperature before deciding as to which insulation is put where

We have qualities knowledge to ensure that this question with solution will definitely help you to achieve perfect score. If you have any MCQ question regarding Mechanical engineering .then drop your questions below and will get back to you in no time.

All questions answers


Leave a Comment