Question

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

a.

ln (r2/r1)/2πLk

b.

ln (r2/r1)/πLk

c.

ln (r2/r1)/2Lk

d.

ln (r2/r1)/2πk

Posted under Heat Transfer

Answer: (a).ln (r2/r1)/2πLk

Interact with the Community - Share Your Thoughts

Uncertain About the Answer? Seek Clarification Here.

Understand the Explanation? Include it Here.

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

Similar Questions

Explore Relevant Multiple Choice Questions (MCQs)

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

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

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?

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

Q. Shape factor for plane wall is equal to

Q. For a prescribed temperature difference, bodies with the same shape factor will allow heat conduction proportional to

Q. Shape factor for cylinder is

Q. The annealing furnace for continuous bar stock is open at the ends and has interior dimensions of 0.6 m * 0.6 m * 1.5 m long with a wall 0.3 m thick all around. Calculate the shape factor for the furnace?

Q. Shape factor for sphere is

Q. Which is true regarding a complete rectangular furnace?

Q. The shape factor for complete rectangular furnace is
Where a, b and c are the inside dimensions and d x is the wall thickness

Q. For the same material and same temperature difference, the heat flow in terms of shape factor is given by

Q. For the same amount of fabrication material and same inside capacity, the heat loss is lowest in

Q. With variable thermal conductivity, Fourier law of heat conduction through a plane wall can be expressed as

Q. The inner and outer surfaces of a furnace wall, 25 cm thick, are at 300 degree Celsius and 30 degree Celsius. Here thermal conductivity is given by the relation
K = (1.45 + 0.5 * 10¯⁵ t²) KJ/m hr deg

Where, t is the temperature in degree centigrade. Calculate the heat loss per square meter of the wall surface area?

Q. A plane wall of thickness δ has its surfaces maintained at temperatures T₁ and T₂. The wall is made of a material whose thermal conductivity varies with temperature according to the relation k = k₀ T². Find the expression to work out the steady state heat conduction through the wall?

Q. The mean thermal conductivity evaluated at the arithmetic mean temperature is represented by

Q. With respect to the equation k = k0 (1 +β t) which is true if we put β = 0?

Q. If β is greater than zero, then choose the correct statement with respect to given relation
k = k0 (1 +β t)

Q. The unit of thermal conductivity doesn’t contain which parameter?

Recommended Subjects

Are you eager to expand your knowledge beyond Heat Transfer? We've handpicked a range of related categories that you might find intriguing.

Click on the categories below to discover a wealth of MCQs and enrich your understanding of various subjects. Happy exploring!