370. Phosphorous is added to copper melt to
A. Remove hydrogen
B. Deoxidise the metal
C. Improve fluidity
D. Reduce shrinkage
✅ The correct answer is option A.
373. Which of the following performance characteristics of a S.I engine is not affected by the front end volatility of the petrol used?
A. Vapour locking
B. Hot starting
C. Spark plug fouling
D. All of the above
✅ The correct answer is option C.
306. Plasma is
A. A high temperature neutral gas
B. Nothing but ionised gas
C. A source of steady and highest controllable pressure
D. Formed at very low temperature
✅ The correct answer is option B.
309. RADAR is
A. Acronym for Radio Detection and Ranging
B. Name of technique for locating distant objects
C. Name of instrument for locating distant objects
D. All of the above
✅ The correct answer is option D.
312. Sheardising process is used for
A. Surface coating
B. Heat treatment of high speed steel
C. Cold working on metals
D. None of these
✅ The correct answer is option A.
315. Stress and strain are related by __________ elastic constants for a linearly elastic, homogeneous & isotropic material.
A. One
B. Two
C. Three
D. Four
✅ The correct answer is option B.
318. Pig iron is
A. Made from cast iron
B. Made from wrought iron
C. The one, which comes out of the blast furnace
D. Free from impurities
✅ The correct answer is option C.
321. The thermal efficiency of a heat engine giving an output of 4 KW with an input of 10000 Joules/sec is __________ percent.
A. 40
B. 80
C. 10
D. 25
✅ The correct answer is option A.
324. Rockwell number represents the
A. Hardness of a substance
B. Colour of a pigment
C. Density of a polymer
D. Active ingredients in a fertiliser
✅ The correct answer is option A.
326. Increase in the entropy of a system represents the
A. Degradation of energy
B. Decrease in system pressure
C. Increase in the availability of energy
D. Increase in the temperature
✅ The correct answer is option A.