ESE (IES) Quiz : Heat and Mass transfer

Question 1

Which one of the following expresses the thermal diffusivity of a substance in terms of thermal conductivity of a substance(k),mass density
() and specific heat (c)?

  • A
  • B
  • C
  • D

Question 2

What is the ratio of thermal conductivity to electrical conductivity equal to?

  • Aprandti number
  • BSchmidt number
  • CLorenz number
  • DLewis number

Question 3

Which one of the following numbers represents the ratio nof kinematic viscosity to the therml diffusivity?

  • AGrashoff number
  • BPrandti number
  • CMach number
  • DNusselt number

Question 4

A thin flat plate 2 m x 2 m is hanging freely in air. The temperature of the the surroundings is. Solar radiation is falling on one side of the plate at the rate of 500 W/m2. What should be the convection heat transfer coefficient in W/m20C, if the temperature of the plate is to remain constant at?

  • A25
  • B50
  • C100
  • D200

Question 5

Fins are used to increase the heat transfer from surface by

  • Aincreasing the temperature difference
  • Bincreasing the effective surface area
  • Cincreasing the convection heat transfer coefficient
  • Dnone of the above

Question 6

A fin length l protrudes from a surface held at temperature T0, it being higher than the ambient temperature Ta. The heat dissipation from the free end of the fin is sated to be negligibly small. What is the temperature gradientat the tip of the fin?

  • AZero
  • B
  • C
  • D

Question 7

Match List –I with List-II and select the correct answer using the code given below the lists:
A) Heat Exchangers
B) Turbulent flow
C) Free convection
D) Radiation heat transfer
1) View factor
2) Effectiveness
3) Nusselt number
4) Eddy diffusivity

  • AA-3; B-1; C-2; D-4
  • BA-2; B-4; C-3; D-1
  • CA-3; B-4; C-2; D-1
  • DA-2; B-1; C-3; D-4

Question 8

Air can be best heated by steam in heat exchanger of

  • Aplate type
  • Bdouble pipe type with fins on steam side
  • Cdouble pipe type with fins on air side
  • Dshell and tube type

Question 9

What is the value of the shape factor for two infinite parallel surface separated by a distance d?

  • A0
  • B
  • C1
  • Dd

Question 10

The time constant of thermocouple is

  • Athe time taken to attain 100% of intial temperature difference
  • Bthe time taken to attain 63.2% of intial temperature difference
  • Cthe time taken to attain 50% of intial temperature difference
  • Dthe minimum time taken to record a temperature reading
Categories: Exams

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