500. Which of the following test is used for distinguishing among dry oils, semi-drying oils and non drying oils?
A. Elaiden test
B. Reichart-Meissl value test
C. Henter value test
D. Iodine value test
✅ The correct answer is option A.
503. With increase in pressure, the latent heat of steam
A. Increases
B. Decreases
C. Remains unchanged
D. Data insufficient; can’t be predicted
✅ The correct answer is option B.
506. Temperature attained in soldering of metals is about __________ °C.
A. 150-300
B. 400-500
C. 650-800
D. 1000-1100
✅ The correct answer is option A.
509. __________ is a special constituent of chlorophyll without which photosynthesis is not possible.
A. Calcium
B. Nitrogen
C. Phosphorous
D. Hydrogen
✅ The correct answer is option B.
512. Filler metal is used in __________ welding.
A. Braze
B. Electric spot
C. Projection
D. Seam
✅ The correct answer is option A.
515. Out of the following, the most melleable material is
A. Copper
B. Aluminium
C. Wrought iron
D. Lead
✅ The correct answer is option D.
518. Which of the following is categorised as the plastic welding?
A. Gas welding
B. Electric arc welding
C. Forge welding
D. None of these
✅ The correct answer is option C.
479. The ability of tool steel to resist softening at high temperatures is termed as __________ hardness.
A. Red
B. Extended
C. Super
D. Extreme
✅ The correct answer is option C.
482. Identify the false statement
A. Martensitic steels are less susceptible to pitting corrosion than austenitic steels
B. Pitting corrosion is usually very localised
C. Hydrogen embrittlement is facilitated by tensile stress
D. Stress corrosion cracking is facilitated by tensile stress
✅ The correct answer is option A.
485. The product (s) of roasting of a sulphide ore is (are)
A. Oxide only
B. Sulphate only
C. Oxide and sulphate
D. Dependent on temperature and partial pressure of oxygen & sulphur dioxide
✅ The correct answer is option A.