A. Temperature
B. Area
C. Nature
D. All ‘A’, ‘B’ & ‘C’
Related Mcqs:
- Maximum amount of thermal radiation is emitted at all wavelengths at any specified temperature by a/an ______________ body?
A. Grey
B. Black
C. Opaque
D. White - For infinite parallel planes having emissivities ε1 & ε2, the interchange factor for radiation from surface 1 to surface 2 is given by__________________?
A. (ε1 + ε2)/ε1.ε2
B. ε1.ε2/(ε1 + ε2 – ε1.ε2)
C. ε1.ε2
D. ε1 + ε2 - Insulation of liquid surface can be achieved by _____________ on top of its surface?
A. Floating hollow polypropylene spheres
B. Spraying alumina powder
C. Putting cement
D. None of these - A thin, flat & square plate measuring 2 m × 2 m is freely hanging in ambient air at 25°C. It is exposed to the solar radiation falling on one side of the plate at the rate of 500 W/m2. The plate temperature will remain constant at 30°C, if the convective heat transfer co-efficient is ________________ W/m2 °C ?
A. 50
B. 100
C. 150
D. 200 - When the wavelength of incident X-rays increases, the angle of diffraction__________________?
A. Decreases
B. Increases
C. Remain constant
D. Shows no systematic variation - Which of the following rays has the least wavelength ?
A. Ultraviolet rays
B. Infrared rays
C. Cosmic rays
D. X-rays - The specific gravity of coal depends mainly on its __________________ content ?
A. Carbon
B. Volatile matter
C. Ash
D. Moisture - Diffusion co-efficient of a metal in a solid solution depends upon its ?
A. Composition
B. Temperature
C. Both A. & B.
D. Neither A. nor B. - Brass parts with high residual tensile stress at the surface are susceptible to season cracking (i.e. spontaneous cracking occuring on exposure to atmospheric corrosion), if its zinc percentage is more than ?
A. 5
B. 10
C. 20
D. 35 - Solidification time of a molten metal in a casting is proportional to (where, V = volume of metal & A = its surface area; in the casting) ?
A. V/A
B. V/A2
C. V2/A
D. V2/A2
