702. __________ welding will be the most suitable for butt welding two 20 cms thick boiler drum mild steel plates.
A. Electrical resistance
B. Electroslag
C. Plasma torch
D. Submerged arc
✅ The correct answer is option B.
704. Which of the following heat treatment processes is usually applied to castings ?
A. Tempering
B. Annealing
C. Normalising
D. Carburising
✅ The correct answer is option D.
706. A highly elastic material is deformed least on loading and retains its original form on removal of the load. Which of the following is the most elastic material?
A. Steel
B. Glass
C. Rubber
D. Brass
✅ The correct answer is option A.
708. Inspection of surface and sub-surface cracks in non-magnetic alloys is done by __________ testing method.
A. X-ray
B. Magnetic particle
C. Dye penetrant
D. Ultrasonic
✅ The correct answer is option C.
710. Heat flow across a hollow sphere of inner radius ‘r₁’ and outer radius ‘r₂’ is directly proportional to
A. (r₂ – r₁)/(r₁ – r₂)
B. (r₂ . r₁)/(r₂ – r₁)
C. (r₁ + r₂)/(r₁ . r₂)
D. (r₁ . r₂)/(r₁ + r₂)
✅ The correct answer is option B.
712. Percentage of differential pressure lost in a venturimeter with a tapering of 15° may be about
A. 1
B. 10
C. 25
D. 50
✅ The correct answer is option B.
714. Specific heat of an ideal gas depends upon its
A. Molecular weight
B. Pressure
C. Temperature
D. Volume
✅ The correct answer is option C.
716. Thermoplastics are never moulded using
A. Injection moulding
B. Blow moulding
C. Extrusion
D. Compression moulding
✅ The correct answer is option D.
718. Silicon percentage in silicon steel used for electrical equipments is about
A. 1
B. 4.0
C. 8
D. 14
✅ The correct answer is option B.
720. Lime contains about 90% CaO. Percentage CaO present in limestone is about
A. 25
B. 50
C. 70
D. 80
✅ The correct answer is option B.