Heat Transfer The heat transfer by radiation from a mild steel surface is to be reduced by reducing the emissivity of the surface. This can be best achieved by Painting the surface black Painting the surface white (with aluminium paint) Giving the surface a mirror finish Roughening the surface Painting the surface black Painting the surface white (with aluminium paint) Giving the surface a mirror finish Roughening the surface ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer A 2-4 heat exchanger involves Both counter and parallel-flow of the fluids Only parallel-flow of fluids Smaller pressure drop compared to 1-2 exchanger Only counter-flow of fluids Both counter and parallel-flow of the fluids Only parallel-flow of fluids Smaller pressure drop compared to 1-2 exchanger Only counter-flow of fluids ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer When does the heat generated by fluid friction becomes appreciable compared to the heat transferred between the fluids? At high fluid velocity At low velocity None of these When fluid flows past a smooth surface At high fluid velocity At low velocity None of these When fluid flows past a smooth surface ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer For a given ambient air temperature with increase in the thickness of insulation of a hot cylinderical pipe, the rate of heat loss from the surface would First decrease and then increase First increase and then decrease Increase Decrease First decrease and then increase First increase and then decrease Increase Decrease ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer A sphere of radius 'R₁' is enclosed in a sphere of radius 'R₂'. The view (or shape) factor for radiative heat transfer of the outer sphere with respect to the inner sphere is R₂/(R₁+R₂) (R₁/R₂)2 1 R₂/(R₁+R₂) (R₁/R₂)2 1 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Heat exchangers operating, when the asymptotic range is reached, Results in abruptly increased velocity Provide very large heat transfer co-efficient None of these Results in making part of the heating surface inactive Results in abruptly increased velocity Provide very large heat transfer co-efficient None of these Results in making part of the heating surface inactive ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS