484. Machine tool bodies are usually made of
A. Cast iron
B. Mild steel
C. Wrought iron
D. Copper alloys
✅ The correct answer is option A.
487. Auto collimator is used to check
A. Flatness
B. Angle
C. Rotor balancing
D. Roughness
✅ The correct answer is option B.
490. Addition of beryllium to copper is done mainly to produce a/an __________ alloy.
A. Non-sparking & non-magnetic
B. High strength
C. Precipitation hardenable
D. Corrosion resistant
✅ The correct answer is option A.
493. The function of neutral flux used in the pyrometallurgy of metal extraction is to increase the __________ of the slag.
A. Fluidity
B. Basicity
C. Acidity
D. Viscosity
✅ The correct answer is option A.
496. With increase in annealing temperature, the following defect density decreases.
A. Vacancy
B. Dislocation
C. Grain boundary
D. All of the above
✅ The correct answer is option D.
459. __________ of test specimens is not involved in any hardness testing method.
A. Fracture
B. Indentation
C. Wear
D. Scratch
✅ The correct answer is option A.
462. Normal dosage of chlorine in public water supply scheme ranges from __________ ppm.
A. 0.5 to 1
B. 10 to 15
C. 300 to 500
D. 1000 to 1500
✅ The correct answer is option A.
427. Which of the following is not an ore of zinc?
A. Cerrusite
B. Franklinite
C. Calamine
D. Troosite
✅ The correct answer is option A.
430. Addition of __________ in steel can help in increasing the depth of hardness.
A. Nickel
B. Chromium
C. Vanadium
D. Tungsten
✅ The correct answer is option C.
433. __________ method of depreciation calculation ensures that the interest is charged on the cost of machine asset every year on the book value, but the rate of depreciation remains constant every year.
A. Annuity charging
B. Atraight line
C. Ainking fund
D. None of these
✅ The correct answer is option B.