Dynamic similarity refers to the similarity of
A.masses and forces
B.velocity and acceleration
C.physical dimensions
D.temperature and heat flux
Category: Heat Transfer Mcqs
The overall co-efficients of heat transfer is used in the problems of
A.convection
B.conduction
C.radiation
D.conduction and convection
The dimensions of thermal conductivity are
A.MLT?3
B.MLT2 ?2
C.MLT-3 ?-1
D.ML-1T2 ?
In a cooling tower which mode of heat transfer plays insignificant role?
A.Evaporative cooling
B.Convective cooling
C.Radiaion
D.All of the above
The equation E = ? AT4 represents
A.Wein’s Law
B.Kirchhoff’s law
C.Stefan Boltzmann’s law
D.None of the above
The overall co-efficient of heat transfer is expressed as
A.kcal/hr
B.kcal/m/hr
C.kcal/m2/hr/?C
D.None of the above
Which liquid metal is supposed to be the best conductor
A.Lead
B.Mercury
C.Zinc
D.Sodium
E.Potassium
The temperature inside a furnace is generally measured by
A.Mercury thermometer
B.Alcohol thermometer
C.Gas thermometer
D.Optical pyrometer
E.Any of the above
A liquid is boiling in a a air tight vessel. Using an exhaust tube, the vapour is pumped out at a faster rate. What happens to the liquid?
A.Temperature goes down, doiling continues
B.Temperature goes up, boiling continues
C.Temperature goes down, boiling stops
D.Temperature goes up, boiling stops
E.Nothing changes
Two rods one of copper and the other of mild steel, both of diameter 20 mm and length 250 mm are coated with a uniform layer of wax all around. These rods are placed vertically in a boiling water bath with 200 mm, length of each rod projecting outside. If the melting point of wax is 10?C, then
A.equal quantity of wax will meet on the two rods
B.more wax will melt on copper rod as compared to mild steel rod
C.more wax will melt on mild steel rod as compared to copper rod
D.nothing can be predioted as the data is insufficient
