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 231 of 350
- A. Collar
- B. Bell and Spigot
- C. Flanged
- D. Expansion
Explanation: A flanged joint can be unbolted easily, making it suitable for temporary cast-iron pipelines that must be dismantled and reassembled…
Correct answer: Flanged- A. High viscosity
- B. Low surface tension
- C. High density
- D. High surface tension
Explanation: Mercury has high surface tension, so cohesive forces pull its surface into the shape with minimum area, producing nearly spherical…
Correct answer: High surface tension- A. Cast iron
- B. Steel
- C. Aluminium
- D. None of these
Explanation: Dry compressed air is commonly used when machining cast iron because liquid coolants can mix with cast-iron dust and create a troublesome…
Correct answer: Cast iron- A. gm . cm2 . sec-2
- B. gm .cm-1 sec-1
- C. gm .cm-2, sec-1
- D. gm . cm . sec-1
Explanation: Dynamic viscosity has dimensions mass per length per time, so in CGS units it is g cm⁻¹ s⁻¹, called the poise.
Correct answer: gm .cm-1 sec-14605. Good design of the casing of a centrifugal pump aims at minimising the __________________________?
- A. Cavitation
- B. Frictional losses
- C. Kinetic energy loss
- D. Static head
Explanation: The casing of a centrifugal pump converts much of the impeller discharge velocity into pressure through gradual deceleration.
Correct answer: Kinetic energy loss- A. Vg
- B. 1/V2
- C. 1/Vg
- D. V2
Explanation: Newton’s law gives shear stress as τ = μ(dV/dy), so it is proportional to the velocity gradient, represented here by Vg.
Correct answer: Vg- A. Upward thrust due to air
- B. Viscous force exerted by air
- C. Surface tension effects of water
- D. Force of gravity
Explanation: As a raindrop accelerates, air resistance increases until it balances the effective downward force, so the drop stops accelerating and…
Correct answer: Viscous force exerted by air- A. Newton's second law of motion
- B. Law of projectiles
- C. Newton's third law of motion
- D. Archimedes principle
Explanation: A rocket ejects gases backward at high velocity, producing an equal and opposite forward reaction on the rocket.
Correct answer: Newton's third law of motion- A. Weight
- B. Head developed
- C. Overall efficiency
- D. Flow output
Explanation: A double-acting reciprocating pump delivers liquid during both strokes, whereas a single-acting pump delivers during only one stroke.
Correct answer: Flow output- A. Density
- B. Surface tension
- C. Viscosity
- D. Buoyancy
Explanation: Hydrostatic pressure increases with liquid density according to p = ρgh, for a specified depth and gravitational field.
Correct answer: Density4611. Which of the following is not the function of a volute casing provided in a centrifugal pump ?
- A. To increase the pump discharge rate
- B. To increase the pump efficiency
- C. To collect liquid from the periphery of the impeller and to transmit it to the delivery pipe at
- D. constant velocity
- E. To reduce the head loss in discharge
Explanation: A volute collects liquid leaving the impeller and converts part of its velocity head into pressure head, improving recovery and…
Correct answer: To increase the pump discharge rate- A. Unsteady uniform
- B. Steady uniform
- C. Unsteady non-uniform
- D. Steady non-uniform
Explanation: During a flood, the river discharge and depth change with time, so the flow is unsteady.
Correct answer: Unsteady non-uniform- A. Laminar flow
- B. Co-current flow
- C. Heat flow rate is independent of nature of flow
- D. Turbulent flow
Explanation: Turbulent flow enhances mixing and reduces the thermal boundary-layer resistance, giving a higher convective heat-transfer coefficient…
Correct answer: Turbulent flow- A. T0.5
- B. T
- C. T1.5
- D. T2
Explanation: Kinetic theory gives gas molecules an average speed proportional to the square root of absolute temperature.
Correct answer: T0.5- A. 10.73 kJ
- B. 16.15 kJ
- C. 18.11 kJ
- D. 18.33 kJ
Explanation: The heat released is obtained by integrating the heat capacity over the temperature drop: Q = 26.693(600) + (7.365 × 10^-3/2)(773.15² −…
Correct answer: 18.11 kJ- A. Hour
- B. Minute
- C. Day
- D. Second
Explanation: One ton of refrigeration is the cooling rate required to melt one ton of ice at 0C in 24 hours.
Correct answer: Day- A. Molten potassium
- B. Molten lead
- C. Mercury
- D. Molten sodium
Explanation: Among the listed liquid metals, molten sodium has the highest thermal conductivity, making it effective for high-temperature heat…
Correct answer: Molten sodium- A. Both A. & B.
- B. Of increased diameter
- C. With greater number of blades
- D. Neither A. nor B.
Explanation: A larger fan with more blades can deliver the required air flow at a lower rotational speed, reducing blade-passage turbulence and noise.
Correct answer: Both A. & B.- A. Shaft furnace
- B. Rotary hearth furnace
- C. Tunnel kiln
- D. Muffle furnace
Explanation: A tunnel kiln provides continuous, controlled preheating and drying of large quantities of refractory bricks as they move through…
Correct answer: Tunnel kiln- A. Sidefired
- B. Recirculating
- C. Covered
- D. Underfired
Explanation: When combustion occurs below the hearth and the hot gases rise into the heating chamber, the furnace is underfired.
Correct answer: Underfired