A. In process heat exchangers, saturated steam is preferred over the superheated steam
B. The maximum is the emissive power of a surface at a temperature T1 occurs at a wavelength
of λ1. If the surface temperature is halved, the maximum in the emissive power would occur at
a wavelength of 0.5 λ1
C. When a vertical plate is heated in infinite air environmental under natural convection
conditions, the velocity profile in air, normal to the plate, exhibits a maximum
D. A body at 925 K emits an energy of 1.42 x 1011ζW/m2 (ζ is the Stefan-Boltzmann constant) in
the wavelength band between 3 μm to 4 μm. The fraction of this energy in the total energy
emitted over the entire wavelength range is equal to emissivity
Correct Answer: B. The maximum is the emissive power of a surface at a temperature T1 occurs at a wavelength
of λ1. If the surface temperature is halved, the maximum in the emissive power would occur at
a wavelength of 0.5 λ1 ✔
Last Updated: March 03, 2019