A. Cracks and blow holes are eliminated
B. Ductility and impact strength improves
C. Appreciable strain hardening is produced
D. Yield stress, hardness and fatigue strength is not at all affected
✅ The correct answer is option D.
Basic Chemical Engineering MCQs
The temperature at which a gas, when subjected to Joule-Thomson expansion, neither cools or heats up, is termed as the __________ temperature. Above this temperature the gas heats up on throttling and below this the gas cools down.
A. Isotactic
B. Saturation
C. Inversion
D. Throttling
✅ The correct answer is option C.
What is the effect on the performance of the economiser in the thermal power plant boiler, if the feed water temperature is very low due to preheaters being out for repairs or starving of steam supply ?
A. It results in corrosion due to the condensation on the flue gas side of the economiser tubes due to handling of low temperature water
B. Economiser tube life increases due to handling of low temperature water
C. Heat transfer efficiency of economiser increases due to picking up high heat from the flue gases
D. Scale formation rate on economiser tubes increases
✅ The correct answer is option A.
The pressure outside a bubble/droplet of liquid is __________ the internal pressure.
A. Greater than
B. Less than
C. Equal to
D. Unpredictable ; depends on the bubble size
✅ The correct answer is option B.
Lead is poured into the joint between two __________ pipes.
A. Mild steel
B. Concrete
C. Cast iron
D. Asbestos cement
✅ The correct answer is option C.
Volume of blast furnace slag is about __________ times the volume of hot metal (pig iron) of the same weight
A. 1.5
B. 3
C. 5
D. 7
✅ The correct answer is option B.
The main constituent of bones is
A. CaF₂
B. Ca₃(PO₄)₂
C. CaCO₃
D. CaCl₂
✅ The correct answer is option B.
Natural water contains approximately __________ percent of heavy water.
A. 0.015
B. 0.71
C. 1.2
D. 3.5
✅ The correct answer is option A.
__________ number is sometimes used in place of Grashoff number in free convection heat transfer.
A. Stanton
B. Brinkman
C. Rayleigh
D. Nusselt
✅ The correct answer is option C.
During sensible heating of humid air
A. Relative humidity increases
B. Dew point remains constant
C. Dry bulb & wet bulb temperature increases
D. Both ‘b’ & ‘c’
✅ The correct answer is option D.