GATE PI 1993
GATE PI
1
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?
2
Manufacturing process $$\,\,\,\,\,\,\,\,\,\,\,\,$$ Property

3
During gas welding of copper sheets a neutral flame was used consuming $$8$$ liters of acetylene. But the weld was found to be defective. So it was re-welded using an oxidizing flame. The likely consumption of oxygen in liters will be
4
The voltage-arc length characteristics of a power source is $$V=20+40L,$$ where $$V=$$ operating voltage in volts and $$L=$$ arc length in $$cm.$$ The open circuit voltage and short circuit current for arc lengths ranging from $$3$$ to $$5mm$$ and current from $$400$$ to $$500$$ amps during welding operation are
5
In a cutting test with $$0.3mm$$ flank wear as tool failure criterion, a tool life of $$10min$$ was obtained at a cutting velocity of $$20m/min.$$ Taking tool life exponrent as $$0.25,$$ the tool life in minutes at $$40m/min$$ of cutting velocity will be
6
A work-piece of $$2000$$ $$mm$$ length and $$300$$ $$mm$$ width was machined by a planning operation with the feed set at $$0.3$$ $$mm/stroke.$$ If the machine tool executes $$10$$ double strokes/min, the planning time for a single pass will be
7
Match the following

8
Match the following

9
Calculate the minimum number of hot rolling passes necessary to reduce an ingot of $$200mm$$ thickness to $$100mm$$ thickness in two high reversible rolling mill with roll diameter is $$500$$ $$mm.$$ The coefficient of friction between the rolls and the hot material is assumed as $$0.20.$$
10
The maximum interference in $$mm$$ after assembly between a bush of size $${30^{\matrix{
{ + 0.06} \cr
{ + 0.03} \cr
} }}$$ and a shaft of size $${30^{\matrix{
{ + 0.04} \cr
{ - 0.02} \cr
} }}$$ is
11
Holes $$1,2,3,4$$ drilled in sequence , with angular positions and tolerances are shown in Figure. Evaluate closing angle $$'X'$$ with its tolerance band.