Heat Conduction in Spherical Shell - MCQS with Answers

1. What is the advantage of using the spherical vessel to store fluids at low temperature?

a. heat transfer in sphere is restricted in all direction by insulation
b. sphere has the smallest volume per unit surface area
c. sphere has the largest volume per unit surface area
d. none of the above

View Answer / Hide Answer


2. What is the correct formula for thermal resistance (R_k) of a spherical shell of inner and outer radii as r_i and r_o respectively and k being the thermal conductivity?

a. R_k= (r_i – r_o ) / 4 π r_i r_o k
b. R_k= 4 π r_i r_o k / (r_i – r_o )
c. R_k= (r_i – r_o ) / 4 π k
d. R_k= r_i r_o / 4 π k (r_i – r_o )

View Answer / Hide Answer


3. What is the formula of the thermal resistance for convection at the outer surface of spherical shell of inner and outer radii as r_i and r_o respectively? Taking h_o as convecting heat transfer coefficient of outer fluid.

a. R_c = 4 π h_o r_o²
b. R_c = 1 / 4 π h_o r_o²
c. R_c = 4 π h_o r_o
d. R_c = 1 / 4 π h_o r_o

View Answer / Hide Answer