1
GATE PI 1991
MCQ (Single Correct Answer)
+1
-0.3
The optimum pouring time for a casting depends on several factors. One important factor among them is
A
location of riser
B
porosity of sand mold
C
fluidity of casting metal
D
area of the pouring basin
2
GATE PI 1991
Subjective
+6
-0
A rectangular block of steel $$C.S$$ $$100\,\, \times \,\,150mm$$ and $$250mm$$ height is to be cast with out any riser. The block is moulded entirely in the drag of a green sand flask & is tap gated. The cope of the flask is $$200mm$$ height & the height of the metal during pouring is $$100mm$$ above the cope level. A tapered sprue is employed & the gating ratio is $$1:4:2$$. Assume no energy losses in the system. The time taken (in seconds) to fill the casting cavity, if the tapered sprues with $$500$$ $$m{m^2}$$ exit area is used.
3
GATE PI 1991
Fill in the Blanks
+1
-0
Pressure die casting deals with casting metals of relatively ............. A ............. melting point and provides ........ B.......... production rate.

A. higher / lower,$$\,\,\,\,\,\,\,\,\,\,$$ B. higher / lower

4
GATE PI 1991
Fill in the Blanks
+1
-0
Low permeability molds and low pouring temperature of the molten metal causes ......................... defect in castings.
EXAM MAP