1
GATE PI 2001
Subjective
+5
-0
For true centrifugal casting process with the axis of rotation in horizontal direction, an acceleration of $$75g,$$ where $$g$$ is the acceleration due to gravity, is required for sound casting. The relation between diameter. $$'D'$$ (in $$mm$$) and the rotational speed $$N$$ ($$1$$ $$rev/s$$) for this casting is $${N^2}D =$$ constant, determine the constant. Also calculate the mold speed (in $$rev/sec(c)$$ for casting $$CI$$ pipes of $$5m$$ long with outside and inside diameters of $$0.52m$$ and $$0.5m$$ respectively
2
GATE PI 1994
Subjective
+5
-0
A cylinder of $$150mm$$ diameter & $$200mm$$ height is to be cast with out any riser. The cylinder is moulded entirely in the drag of a green sand flask & is top gated. The cope of the flask is $$200mm$$ height & the height of the metal during pouring is $$50mm$$ above the cope. A tapered sprue is employed & the gating ratio is $$1:1.5:2$$. The time taken (in seconds) to fill the casting cavity neglecting energy losses, if the in-gate area is $$400sq.mm$$
3
GATE PI 1993
Subjective
+5
-0
A casting of $$200\,\,mm\,\, \times \,\,100\,\,mm \times 70\,\,mm$$ size solidifies in ten minutes. Estimate solidification time for a $$200\,\,mm\,\, \times \,\,100\,\,mm \times 10\,\,mm$$ casting under similar conditions?
4
GATE PI 1992
+5
-1.5
If the freezing ratio equal to (casting area/casting volume)/(riser area/riser volume) & the volumetric ratio equal to riser volume/casting volume, for a disc casting of $$20cm$$ diameter and $$10$$ $$cm$$ thick are $$1.4$$ and $$0.8$$ respectively. The corresponding values for a square disc of $$20$$ $$cm$$ side and $$10$$ $$cm$$ thick if the same cylindrical riser with a height to diameter ratio of unity is used in both cases.
A
$$1.4$$ & $$0.68$$
B
$$1.4$$ & $$0.8$$
C
$$1.2$$ & $$0.8$$
D
$$1.2$$ & $$0.68$$
GATE PI Subjects
Fluid Mechanics
Metrology
Theory of Machines
Engineering Mathematics
Heat Transfer
Machine Tools and Machining
Industrial Engineering
Engineering Mechanics
Strength of Materials
Thermodynamics
Machine Design
Casting
Joining of Materials
Metal Forming
EXAM MAP
Joint Entrance Examination