Reflective sheet materials used as thermal insulating material have                         reflectivity and                      emissivity.

Related MCQs

• Presence of moisture in the thermal insulating material increases thermal insulation while the presence of air spaces decreases thermal insulation.
• Which of the following is not a quality of a good thermal insulating material?
• A GaAs injection laser with an optical cavity has refractive index of 3.6. Calculate the reflectivity for normal incidence of the plane wave on the GaAs-air interface.
• Which of the following is the correct relationship between thermal resistance and thermal conductivity?
• Which of the following is the correct relation between thermal transmittance and thermal time constant?
• A burning wood in the fireplace has a surface temperature of 450°C. Assume the emissivity to be 1 and find the radiant emission of energy per unit area.
• 5 cm in diameter, through which 400 W of electric energy is deposited. Assume the surface emissivity to be 0.9 and neglecting incoming radiation, find the rod surface temperature?
• What relation between emissivity, e, and Absorptive Power, a, is given by Kirchhoff’s law?
• Batch collectors reduce heat loss by thermally insulating the storage tank.
• For an object other than a black body, it’s emissivity, e is