1
GATE ME 2014 Set 3
MCQ (Single Correct Answer)
+2
-0.6
A solid sphere of radius$${r_1} = 20\,\,mm$$ is placed concentrically inside a hollow sphere of radius $${r_2} = 30\,\,mm$$ as shown in the figure. GATE ME 2014 Set 3 Heat Transfer - Radiation Question 15 English

The view factor $${F_{21}}$$ for radiation heat transfer is

A
$$2/3$$
B
$$4/9$$
C
$$8/27$$
D
$$9/4$$
2
GATE ME 2013
MCQ (Single Correct Answer)
+2
-0.6
Two large diffuse gray parallel plates, separated by a small distance, have surface temperatures of $$400$$ $$K$$ and $$300$$ $$K.$$ If the emissivities of the surfaces are $$0.8$$ and the Stefan-Boltzmann constant is $$5.67 \times {10^{ - 8}}$$ $$W/{m^2}{K^4},$$ the net radiation heat exchange rate in $$kW/{m^2}$$ between the two plates is
A
$$0.66$$
B
$$0.79$$
C
$$0.99$$
D
$$3.96$$
3
GATE ME 2012
MCQ (Single Correct Answer)
+2
-0.6
Consider two infinitely long thin concentric tubes of circular cross section as shown in the figure. If $${D_1}$$ and $${D_2}$$ are the diameters of the inner and outer tubes respectively, then the view factor $${F_{22}}$$ is given by GATE ME 2012 Heat Transfer - Radiation Question 18 English
A
$$\left( {{{{D_2}} \over {{D_1}}}} \right) - 1$$
B
Zero
C
$$\left( {{{{D_1}} \over {{D_2}}}} \right)$$
D
$$1 - \left( {{{{D_1}} \over {{D_2}}}} \right)$$
4
GATE ME 2009
MCQ (Single Correct Answer)
+2
-0.6
Radiative heat transfer is intended between the inner surfaces of two very largen isothermal parallel metal plates. While the upper plate (designated as plate $$1$$) is a black surface and is the warmer one being maintained at $${727^ \circ }C,$$ the lower plate (plate $$2$$) is a diffuse and gray surface with an emissivity of $$0.7$$ and is kept at $${27^ \circ }C.$$ Assume that the surfaces are sufficiently large to form a two-surface enclosure and steady state conditions to exist. Stefan Boltzmann constant is given as
$$5.67 \times {10^{ - 8}}\,W/{m^2}{K^4}$$

The irradiation (in $$kW/{m^2}$$) for the upper plate is

A
$$2.5$$
B
$$3.6$$
C
$$17.0$$
D
$$19.5$$
GATE ME Subjects
Turbo Machinery
EXAM MAP
Medical
NEETAIIMS
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12