Pick out the wrong statement.
Convective heat transfer co-efficient in case of fluid flowing in tubes is not affected by the tube length/diameter ratio, if the flow is in the __________ zone.
The actual temperature drop across the heating surface in an evaporator depends on the
Which of the following is not used as a medium for high temperature heating ?
Presence of a non-condensing gas in a condensing vapour
The average heat transfer co-efficient for laminar film condensation on vertical surface is inversely proportional to (where, ΔT = Temperature drop across condensate film )
Bulk of the convective heat transfer resistance from a hot tube surface to the fluid flowing in it, is
The equivalent diameter for pressure drop is __________ that for heat transfer.
Which of the following is concerned with both heat and mass transfer ?
A backward feed multiple effect evaporator is better than forward feed for concentrating cold feed, because it provides
Controlling heat transfer film co-efficient is the one, which offers __________ resistance to heat transfer.
Acm dia steam pipe, carrying steam at 180°C, is covered with an insulation (conductivity = 0.6 W/m.°C). It losses heat to the surroundings at 30°C. Assume a heat transfer co-efficient of 0.8 W/m2.°C for heat transfer from surface to the surroundings. Neglect wall resistance of the pipe and film resistance of steam. If the insulation thickness is 2 cms, the rate of heat loss from this insulated pipe will be
The heat flux (from outside to inside) across an insulating wall with thermal conductivity, K= 0.W/m.°K and thickness 0.isW/m2. The temperature of the inside wall is - 5°C. The outside wall temperature is
Thermal conductivity of a conducting solid material depends upon its
Pick out the wrong statement.
Shell side pressure drop in a shell and tube heat exchanger does not depend upon the
When vaporisation takes place directly at the heating surface, it is called
Hot water (0.m3 /min) enters the tube side of a counter current shell and tube heat exchanger at 80°C and leaves at 50°C. Cold oil (0.m3/min) of densitykg/m3 and specific heat of 2 kJ/kg.K enters at 20°C. The log mean temperature difference in °C is approximately
The unit of heat transfer co-efficient in SI unit is
Kirchoff s law applies to __________ radiation.
In the equation Q = UAΔt; Δt is
With increase in porosity, the thermal conductivity of a solid substance
Reynold's analogy states that
In a heat exchanger, floating head is provided to
The number of kg vaporised per kg of steam fed to the evaporator is defined as
With the increase of temperature, the Col-burn jH factor
In case of evaporators, liquid entrainment results primarily due to
Fouling factor
Crystal size in a continuous crystalliser depends upon the
For an ideal black body
In Joule's experiment, an insulated container containskg of water initially at 25°C. It is stirred by an agitator, which is made to turn by a slowly falling body weighingkg through a height of 4 m. The process is repeatedtimes. The acceleration due to gravity is 9.8 ms-2. Neglecting the heat capacity of agitator, the temperature of water (in °C) is
With increase in temperature, the thermal conductivity of non-metallic amorphous solids
Leidenfrost point is a term concerned with the