What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m. °K ? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively.

What is the critical radius of insulation (cms) for a metallic cylinde

1.	What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m. °K ? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively.
A.	2
B.	5
C.	10
D.	20
Answer» B. 5

Discussion

No Comment Found

Related MCQs

Resistance of an electrical conductor is proportional to its (where, = length and = cross-sectional area of the conductor)
In troposphere (the weather domain), the temperature '' at height '' above the sea level in metres is given by (where, temperature at sea level is 15°C and is in °C.)
A high pressure boiler generates steam at a pressure greater than __________ kg/cm .
Nusselt number is related to Grashoff number () in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as
Percentage of differential pressure lost in a venturimeter with a tapering of 15° may be about
Velocity of a gas in sound is not proportional to (where, = Absolute temperature of the gas. = Absolute pressure of the gas. = Ratio of specific heats (/) ρ = specific weight of the gas)
Maximum heat dissipation occurs from a steel wire ( = 0.5 W/m. k) of 15 mm diameter exposed to air ( = 20W/m .k), when the insulation thickness is __________ mm.
A thin, flat & square plate measuring 2 m x 2 m is freely hanging in ambient air at 25°C. It is exposed to the solar radiation falling on one side of the plate at the rate of 500 W/m . The plate temperature will remain constant at 30°C, if the convective heat transfer co-efficient is __________ W/m °C.
Solidification time of a molten metal in a casting is proportional to (where, = volume of metal & = its surface area ; in the casting)
In Newton's law of viscosity, which states that the shear stress is proportional to the __________ Co-efficient of viscosity is called dynamic or absolute viscosity(where, = velocity, = velocity gradient ).

What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m. °K ? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively.

Discussion

No Comment Found

Related MCQs

Reply to Comment