What is the type of welding defect caused due to shrinkage during solidification and by weld stresses called?
Answer: B
Lamellar tearing is caused due to shrinkage during solidification and by weld stresses.
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The material property which depends only on the basic crystal structure is
Answer: C
Fracture strength is a material property which depends on the basic crystal structure. Fracture strength depends on the strength of the material.
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If a gas metal arc process uses a low arc voltage and the arc is continuously interrupted as the molten electrode metal fills up the arc gap is known as
Answer: B
In short ARC, Gas metals are processes use a law are voltage. The arc is continuously interrupted as the molten electrode metal bridges the arc gap.
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Which of the following statement is wrong about ultrasonic machining?
Answer: C
No answer description available for this question.
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Calculate the weld per minute, work speed of circular electrode of 220 mm diameter for carrying out seam welding at 4 welds per cm on 1.6 mm thick mild steel tube. Welding cycle consists of 3 cycles ‘on’ and 2 cycles ‘off’ Power supply is at 50 Hz.
Answer: B
Weld per min = (frequency × 60)/ (cycles for weld + interval cycles)
= (50 × 60)/ (3 + 2) = 600 welds/ min.
Work speed (mm / min) = (welds/ min) / weld required per mm
= 600 / (4/10) = 1500 mm/min.
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In a particular type of welding, flux is prepared in the form of a coarse powder and granulated flux is spread over the joint. What is this type of welding process called?
Answer: B
In submerged type of arc welding, flux is prepared in the form of coarse powder granulated flux is spread over the joint.
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A solid cylinder of diameter 100 mm and height 50 mm is forged between two frictionless flat dies to a height of 25 mm. The percentage change in diameter is
Answer: D
Since volume of cylinder remains same.
Therefore, Volume before forging = Volume after forging
πd₁⊃2;/ 4 = πd₂⊃2;/ 4
Or, d₂ = 141.42
Percentage change in diameter = {(d₂ - d₁)/ d₁} × 100
= 41.42%
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In orthogonal turning of a low carbon steel bar of diameter 150 mm with uncoated carbide tool, the cutting velocity is 90 m/min. The feed is 0.24 mm/rev and the depth of cut is 2 mm. The chip thickness obtained is 0.48 mm. If the orthogonal rake angle is zero and the principle cutting edge angle is 90⁰, the shear angle in degree is
Answer: B
Given: D = 150 mm, V = 90 m/min, f = 0.24 mm/rev.
d = 2mm, tc = 0.48 mm, α = 0, λ= 90⁰
Uncut chip thickness, t = f sin λ = 0.24 × sin90⁰ = 0.24 mm
Chip thickness ratio, r = t/tc = (0.24/ 0.48) = 1/2
From merchant’s theory,
Shear angle, tanΦ = rcos α /(1 - sin α) = 0.5cos0⁰/ (1 - 0.5sin0⁰) = 0.5
Φ = tan⁻⊃1; (0.5) = 26.56⁰
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The cutting force in punching and blanking operations mainly depends on
Answer: B
The blanking force is given by the relation,
Fb = τ × d × t
Where, τ = shear strength of material.
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The common welding error that occurs due to shrinkage of weld metal, faulty clamping of parts, faulty penetration or overheating at joints is called?
Answer: B
Warping occurs due to shrinkage of weld metal, faulty clamping of parts, faulty penetration or overheating at joint.
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