GATE ME 2022 Set 1 | Radiation Question 4 | Heat Transfer

GATE ME 2022 Set 1

Numerical

-0

A flat plate made of cast iron is exposed to a solar flux of 600 W/m²at an ambient temperature of 25 °C. Assume that the entire solar flux is absorbed by the plate. Cast iron has a low-temperature absorptivity of 0.21. Use Stefan-Boltzmann constant = 5.669 × 10^-8 W/m²-K⁴. Neglect all other modes of heat transfer except radiation. Under the aforementioned conditions, the radiation equilibrium temperature of the plate is __________ °C (round off to the nearest integer).

Your input ____

GATE ME 2017 Set 2

MCQ (Single Correct Answer)

-0.3

The emissive power of a blackbody is $$P.$$ If its absolute temperature is doubled, the emissive power becomes

$$2P$$

$$4P$$

$$8P$$

$$16$$$$P$$

GATE ME 2016 Set 2

MCQ (Single Correct Answer)

-0.3

Consider the radiation heat exchange inside an annulus between two very long concentric cylinders. The radius of the outer cylinder is $${R_0}$$ and that of the inner cylinder is $${R_i}$$ . The radiation view factor of the outer cylinder onto itself is

$$1 - \sqrt {{{{R_i}} \over {{R_0}}}} $$

$$\sqrt {1 - {{{R_i}} \over {{R_0}}}} $$

$$1 - {\left( {{{{R_i}} \over {{R_0}}}} \right)^{1/3}}$$

$$1 - {{{R_i}} \over {{R_0}}}$$

GATE ME 2012

MCQ (Single Correct Answer)

-0.3

For an opaque surface, the absorptivity $$\left( \alpha \right),$$ transmissivity $$\left( \tau \right)$$ and reflectivity $$\left( \rho \right)$$ are related by the equation:

$$\alpha + \rho = \tau $$

$$\rho + \alpha + \tau = 0$$

$$\alpha + \rho = 1$$

$$\alpha + \rho = 0$$

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