With increase in temperature, the thermal conductivity of steel___________________?

A. Higher economy
B. Lower capacity
C. Both A. & B.
D. Lower economy

A. Increases the rate of condensation
B. Decreases thermal resistance
C. Is desirable to increase the film co-efficient
D. None of these

A. Is a dimensionless quantity
B. Does not provide a safety factor for design
C. Accounts for additional resistances to heat flow
D. None of these

A. Prandtl number
B. Grashoff number
C. Thermal conductivity
D. Viscosity

A. 1.49
B. 1
C. 4.88
D. None of these

A. Temperature gradient of the wall to that across the entire pipe
B. Temperature difference to the temperature gradient at the wall
C. Heat flux at the wall to that across the entire pipe
D. None of these