289. The quantity of electricity required to deposit one gm equivalent of any substance is one
A. Ampere
B. Coulomb
C. Microfaraday
D. Faraday
✅ The correct answer is option D.
292. Theoretical volume of oxygen required for complete combustion of 1Nm³ of acetylene, in oxy-acetylene welding is __________ Nm³ .
A. 0.5
B. 1
C. 2
D. 2.5
✅ The correct answer is option D.
295. A furnace is made of a refractory brick wall of thickness 0.5 metre and thermal conductivity 0.7 W/m.°K For the same temperature drop and heat loss, this refractory wall can be replaced by a layer of diatomaceous earth of thermal conductivity 0.14 W/m.K and thickness __________ metre.
A. 0.01
B. 0.1
C. 0.25
D. 0.5
✅ The correct answer is option B.
298. The dew point temperature lines on psychrometric charts are straight inclined sloping downwards to the right. When relative humidity of moist air is 100%, then
A. Wet bulb temperature=dry bulb temperature
B. Wet bulb temperature=dew point temperature
C. Saturation temperature=dew point temperature
D. All of the above
✅ The correct answer is option D.
301. Hardening of steel is not possible, unless it is heated __________ critical point.
A. Above the highest
B. Above the lowest
C. Between the first & second
D. Between the second & third
✅ The correct answer is option B.
266. Out of the following materials, the one which generally exhibits an yield point is
A. Hard bronze
B. Soft brass
C. Cold rolled mild steel
D. Hot rolled mild steel
✅ The correct answer is option D.
269. Out of the following, __________ pipe is the least corrosion resistant.
A. Mild steel
B. Copper
C. Wrought iron
D. Stainless steel
✅ The correct answer is option C.
271. Shrinkage allowance on pattern is provided to compensate for shrinkage when the
A. Metal changes from liquid state to solid state at freezing temperature
B. Solid phase temperature drops from freezing temperature to the room temperature
C. Liquid metal temperature drops from pouring temperature to room temperature
D. Liquid metal temperature drops from pouring temperature to freezing temperature
✅ The correct answer is option B.
273. Galvanic corrosion can not be prevented by
A. Cathodic protection
B. Anodic protection
C. Usage of largest possible anodic area
D. Any one of these
✅ The correct answer is option B.
275. Maxwell’s thermodynamic relations applies to the
A. Chemical systems in equilibrium
B. Mechanical systems in equilibrium
C. Irreversible thermodynamic processes
D. Reversible thermodynamic processes
✅ The correct answer is option A.