1
GATE ME 1995
Subjective
+5
-0
Consider two large parallel plates, one at $${T_1} = {727^ \circ }C$$ with emissivity $${\varepsilon _1} = 0.8$$ and the other at $${T_2} = {227^ \circ }C\,$$ with emissivity $${\varepsilon _2} = 0.4.$$ An aluminium radiation shield with an emissivity, $${\varepsilon _s} = 0.05$$ on both sides is placed between the plates. Calculate the percentage reduction in heat transfer rate between the two plates as a result of the shield.
Use $$\sigma = 5.67 \times {10^{ - 8}}W/\left( {{m^2}{K^4}} \right)$$
2
GATE ME 1995
Subjective
+5
-0
A counter flow heat exchanger is to heat air entering at $${400^ \circ }C$$ with a flow rate of $$6$$ $$kg/s$$ by the exhaust gas entering at $${800^ \circ }C$$ with a flow rate of $$4$$ $$kg/s$$. The overall heat transfer coefficient is $${100^ \circ }C$$ $$W/\left( {{m^2}K} \right)$$ and the outlet temperature of the air is $${551.5^ \circ }C.$$ Specific heat at constant pressure for both air and the exhaust gas can be taken as $$1100$$ $$J/(kgK).$$ Calculate the heat transfer area needed and the number of transfer units.
3
GATE ME 1995
MCQ (Single Correct Answer)
+1
-0.3
If the demand for an item is doubled and the ordering cost halved, the economic order quantity
A
remains unchanged
B
increases by a factor of $$\sqrt 2 $$
C
is doubled
D
is halved
4
GATE ME 1995
Subjective
+5
-0
Consider the following data for a product:
Demand $$=1000$$ units/year
Order cost $$=$$ Rs.$$40$$/order
Holding cost $$ = 10\% $$ of the unit cost / unit-year
Unit cost $$=$$ Rs.$$500$$

(a) What is the economic order quantity?
(b) Under the $$EOQ$$ what is the number of annual orders?
(c) With a policy of ordering every month what would be the total annual cost as a percentage of the cost at $$EOQ$$?

EXAM MAP
Medical
NEET
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
CBSE
Class 12