## HEAT AND MASS TRANSFER MCQ

SECTION-4

##### Q41. The rate of heat transfer is constant if

(a) temperature decreases with time
(b) temperature increases with time
(c) temperature is constant with time
(d) none of the above.

Ans:(c) temperature is constant with time

##### Q42. The rate of heat transfer is variable if

(a) temperature decreases with time
(b) temperature increases with time
(c) temperature is constant with time
(d) temperature changes with time.

Ans:(d) temperature changes with time.

##### Q43. If the rate of heat transfer is constant, it is known as

(a) steady-state heat transfer
(b) unsteady-state heat transfer
(c) uniform heat transfer
(d) non-uniform heat transfer.

Ans:(a) steady-state heat transfer

##### Q44. If the rate of heat transfer is variable, it is known as

(a) steady-state heat transfer
(b) unsteady-state heat transfer
(c) uniform heat transfer
(d) non-uniform heat transfer.

Ans:(b) unsteady-state heat transfer

##### Q45. The process of heat transfer, from one particle of the body to another without actual motion of the particle, is called

(b) convection
(c) conduction
(d) none of the above.

Ans:(c) conduction

##### Q46. A furnace wall of thickness 1 m and of surface area 2 m2, is made of a material whose thermal conductivity is 1/4kcal/hr m°C. The temperature of inner surface of the wall is 1000°C and of outer surface 200°C. The heat flow through the wall is

(a) 500 kcal/hr
(b) 400 kcal/hr
(c) 300 kcal/hr
(d) 200 kcal/hr.

Ans:(b) 400 kcal/hr

##### Q47. A composite wall of three hetrogeneous layers of thickness 0.3 m, 0.2 m, 0.15 m and of thermal conductivities 0.3, 0.2, 0.15 kcal/hr m°C is having surface are 1.0 m2. If the inner and outer temperatures of the composite wall are 1000°C and 40°C, the rate of heat flow willbe equal to

(a) 300 kcal/hr
(b) 200 kcal/hr
(c) 320 kcal/hr
(d) 500 kcal/hr.

Ans:(c) 320 kcal/hr

##### Q48. The unit of film heat transfer coefficient (h) in MKS is

(a) kcal/m2 hr°C
(b) kcal/m hr°C
(c) kcal/hr°C
(d) kcal m/hr°C.

Ans:(a) kcal/m2 hr°C

##### Q49. For the same temperature difference, the rate of heat transfer through a hollow cylinder of inner and outer radii r1 and r2 respectively, increases as the ratio (r2/r1 )

(a) increases
(b) decreases
(c) constant
(d) none of above.

Ans:(b) decreases

##### Q50. The termρVL/μ is called

(a) Reynold number
(b) Nusselt number
(c) Prandtl number
(d) Froude number.

Ans:(a) Reynold number

1      2      3      4          6      7     8

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##### Read More Sections of Heat Transfer and Mass Transfer

Each section contains maximum 80 Questions. To practice more questions visit other sections.

Heat and Mass Transfer, RAC  MCQ – Section-1

Heat and Mass Transfer, RAC  MCQ – Section-2

Heat and Mass Transfer, RAC  MCQ – Section-3

Heat and Mass Transfer, RAC  MCQ – Section-4