Q. Typical examples of heat conduction through cylindrical tubes are not found in

View solution

Q. The rate of heat conduction through a cylindrical tube is usually expressed as

View solution

Q. Logarithmic mean area of the cylindrical tube is given as

View solution

Q. A hot fluid is being conveyed through a long pipe of 4 cm outer diameter and covered with 2 cm thick insulation. It is proposed to reduce the conduction heat loss to the surroundings to one-third of the present rate by further covering with same insulation. Calculate the additional thickness of insulation

View solution

Q. The heat flow equation through a cylinder of inner radius r1 and outer radius r2 is desired to be written in the same form as that for heat flow through a plane wall. For wall thickness (r₂-r₁) the area will be

View solution

Q. A cylinder of radius r and made of material of thermal conductivity k 1 is surrounded by a cylindrical shell of inner radius r and outer radius 2r. This outer shell is made of a material of thermal conductivity k 2. Net conductivity would be

View solution

Q. For steady state and constant value of thermal conductivity, the temperature distribution associated with radial convection through a cylinder is

View solution

Q. A cylindrical cement tube of radii 0.05 cm and 1.0 cm has a wire embedded into it along its axis. To maintain a steady temperature difference of 120 degree Celsius between the inner and outer surfaces, a current of 5 ampere is made to flow in the wire. Find the amount of heat generated per meter length. Take resistance of wire equal to 0.1 ohm per cm of length

View solution

Q. A stainless steel tube with inner diameter₁2 mm, thickness 0.2 mm and length 50n cm is heated electrically. The entire 15 k W of heat energy generated in the tube is transferred through its outer surface. Find the intensity of current flow

View solution

Q. The temperature distribution associated with radial conduction through a sphere is represented by

View solution

Q. The thermal resistance for heat conduction through a spherical wall is

View solution

Q. The rate of conduction heat flow in case of a composite sphere is given by

View solution

Q. The thermal resistance for heat conduction through a hollow sphere of inner radius r1 and outer radius r2 is

View solution

Q. A spherical vessel of 0.5 m outside diameter is insulated with 0.2 m thickness of insulation of thermal conductivity 0.04 W/m degree. The surface temperature of the vessel is – 195 degree Celsius and outside air is at 10 degree Celsius. Determine heat flow per m² based on inside area

View solution

Q. The quantity d t/Q for conduction of heat through a body i.e. spherical in shape is

View solution

Q. A spherical vessel of 0.5 m outside diameter is insulated with 0.2 m thickness of insulation of thermal conductivity 0.04 W/m degree. The surface temperature of the vessel is – 195 degree Celsius and outside air is at 10 degree Celsius. Determine heat flow

View solution

Q. If we increase the thickness of insulation of a circular rod, heat loss to surrounding due to

View solution

Q. The following data pertains to a hollow cylinder and a hollow sphere made of same material and having the same temperature drop over the wall thickness

Inside radius = 0.1 m and outside surface area = 1 square meter

If the outside radius for both the geometrics is same, calculate the ratio of heat flow in the cylinder to that of sphere?

View solution

Q. “All the factors relating to geometry of the sections are grouped together into a multiple constant called the shape factor” True or false

View solution

Q. Shape factor for plane wall is equal to

View solution