All Free Chemical Engineering MCQs with Answers
Every Chemical Engineering question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
6,983 questions · page 324 of 350
- A. Thermal
- B. Tensile
- C. Compressive
- D. Shear
Explanation: When a bar is prevented from expanding or contracting freely, temperature change creates thermal stress.
Correct answer: Thermal- A. 0.85
- B. 1
- C. 1.5
- D. < 0.5
Explanation: A seamless pipe has no welded joint whose strength must be discounted, so its joint efficiency is taken as unity.
Correct answer: 1- A. More
- B. Same
- C. Less
- D. More or less depending upon the pressure & temperature inside the vessel and the nature of
- E. the fluid contained therein
Explanation: The cylindrical shell must withstand the liquid head and hoop stress over the vessel height, so it is normally thicker than the roof and…
Correct answer: Less- A. Thick spherical
- B. Tall vertical
- C. Thick walled vertical
- D. Horizontal cylindrical
Explanation: Saddle supports distribute the load of a horizontal cylindrical vessel along two supporting regions and reduce local shell stress.
Correct answer: Horizontal cylindrical- A. Gas flow rate
- B. Electrode area
- C. Both A. & B.
- D. Neither A. nor B.
Explanation: For an electrostatic precipitator, collection efficiency increases with collecting electrode area because more surface is available for…
Correct answer: Electrode area- A. If its diameter is more than 50 meters
- B. If its diameter is less than 15-20metres
- C. If the thickness of the roof is more than that of the cylindrical shell
- D. Irrespective of its diameter
Explanation: A self-supporting conical roof is practical for relatively small storage tanks, commonly when the diameter is below about 15 to 20 m.
Correct answer: If its diameter is less than 15-20metres- A. Be fabricated very easily
- B. Withstand higher pressure for a given metallic shell thickness
- C. Be designed without wind load considerations
- D. Be supported very easily
Explanation: A sphere distributes internal pressure uniformly and develops lower membrane stress than a cylindrical vessel for the same wall thickness…
Correct answer: Withstand higher pressure for a given metallic shell thickness- A. Brackets
- B. Skirts
- C. Saddles
- D. Columns
Explanation: Saddles support horizontal vessels, whereas vertical vessels are commonly supported by skirts, brackets, or columns.
Correct answer: Saddles- A. Strain
- B. None of these
- C. Modular ratio
- D. Stress
Explanation: Young's modulus is stress divided by strain; since strain is dimensionless, its units are the same as stress, such as Pa or N/m².
Correct answer: Stress- A. All A., B. and C.
- B. Greater cost for the reboiler heat supply
- C. Greater cost for the condenser coolant
- D. Lower fixed charges for the column
Explanation: A higher reflux ratio reduces the number of theoretical stages, so the column may require lower fixed investment, but it increases both…
Correct answer: All A., B. and C.- A. Torispherical
- B. Elliptical
- C. Hemispherical
- D. None of these
Explanation: A hemispherical head has the most favorable curvature and distributes membrane stress efficiently, allowing it to withstand the greatest…
Correct answer: Hemispherical- A. 30°
- B. 45°
- C. 60°
- D. 75°
Explanation: A 60° apex angle is the usual standard for conical bottom heads because it provides effective solids drainage while remaining practical to…
Correct answer: 60°- A. Both A. and B.
- B. Is easy to fabricate
- C. Has greater structural strength
- D. Neither A. nor B.
Explanation: Cylindrical tanks distribute pressure and structural loads efficiently, giving greater strength than rectangular vessels, and their curved…
Correct answer: Both A. and B.- A. 3 to 4
- B. 1.5 to 2
- C. 4 to 5
- D. > 5
Explanation: Hydrostatic or pressure testing is commonly carried out at about 1.5 times the design pressure to verify vessel strength and leak…
Correct answer: 1.5 to 2- A. Half
- B. Equal to
- C. Twice
- D. Eight times
Explanation: For a thin cylindrical vessel, hoop stress is pD/(2t), whereas longitudinal stress is pD/(4t).
Correct answer: Twice- A. 5 mm
- B. 6 mm
- C. 8 mm
- D. 10 mm
Explanation: With L/D = 3, the vessel dimensions are D = 2 m and L = 6 m. The cylindrical-shell pressure thickness is about 8 mm, and adding the 2 mm…
Correct answer: 10 mm- A. Small
- B. Tall but empty
- C. Large horizontal cylindrical
- D. Thick walled tall
Explanation: Lug supports are commonly used for relatively small vessels, where welded lugs provide a simple support without the heavier skirt…
Correct answer: Small- A. 0.01
- B. 0.3
- C. 0.75
- D. 0.95
Explanation: Structural and pressure-vessel steels have Poisson's ratio close to 0.3, meaning lateral contraction is about 30% of the axial elastic…
Correct answer: 0.3- A. d = 1.1 t
- B. d = 3 √t
- C. d = 1.5 t
- D. d = 1.6 √t
Explanation: Unwin’s formula for the rivet-hole diameter is d = 1.6√t, with both d and t in millimetres.
Correct answer: d = 1.6 √t- A. Cross-sectional area
- B. Changes in temperature
- C. Both A. and B.
- D. Neither A. nor B.
Explanation: For a fully restrained bar, thermal stress is σ = EαΔT, so it depends on the temperature change and material properties but not on…
Correct answer: Cross-sectional area