1
GATE PI 1991
Subjective
+5
-0
A resistance welder is rated at $$50$$ $$kVA,$$ at $$50\% $$ duty cycle. Secondary voltage is always constant at $$25$$ volts. If a job requires $$1500$$Amps current, determine the maximum welding time in a total cycle time of $$30$$$$secs$$.
2
GATE PI 1991
Fill in the Blanks
+1
-0
In spot welding of aluminium sheets, the welding current should be .........A........ and weld time should be kept ............B......... than for $$MS$$ sheet of same thickness.

(A). higher / lower, (B). higher / lower

3
GATE PI 1991
Fill in the Blanks
+1
-0
....................... is the non-fusion method of joining dissimilar metals with metals whose melting temp is greater than $${400^ \circ }C$$.
4
GATE PI 1991
Fill in the Blanks
+1
-0
Increase in rake angle causes ..........A................ in chip thickness and .............B......... in shear angle

(a) increase / reduction
(b) increase / decrease