Question: The main pollutant in waste water discharged from a petroleum refinery is oil (both in free and emulsified form). Free oil is removed by_________________?

• 1. Biological oxygen pond
• 2. Aerated lagoons
• 3. Trickling filters
• 4. Gravity separator having oil skimming devices

Question: Pick out the correct statement ?

• 1. Deforestation helps in controlling the green house effect
• 2. Global warming is detrimental for increase in food productivity and may cause flood andcyclone
• 3. Lightening discharges are natural source of production of SO2 & H2S pollutant
• 4. Sulphur dioxide causes death by asphyxiation

Question: Baffles in the shell side of a shell and tube heat exchanger ?

• 1. Increase the cross-section of the shell side liquid
• 2. Force the liquid to flow parallel to the bank
• 3. Increase the shell side heat transfer co-efficient
• 4. Decrease the shell side heat transfer co-efficient

Question: For turbulent flow in a tube, the heat transfer co-efficient is obtained from the Dittus- Boelter correlation. If the tube diameter is halved and the flow rate is doubled, then the heat transfer co-efficient will change by a factor of________________?

• 1. 1
• 2. 1.74
• 3. 6.1
• 4. 37

Question: What is the steam economy in case of a single effect evaporator system ?

• 1. 1
• 2. > 1
• 3. < 1
• 4. 0.1

Question: Vibrations in the tubes of a shell and tube heat exchanger is induced due to the _________________?

• 1. Flow of fluid on the tube and shell sides
• 2. Oscillations in the flow of shell/tube sides fluid
• 3. Vibrations transmitted through piping and/or supports due to external reasons
• 4. All A, B & C

Question: The ratio of kinematic viscosity to thermal diffusivity is called the _______________ number?

• 1. Peclet
• 2. Prandtl
• 3. Stanton
• 4. Nusselt

Question: A fluid is flowing inside the inner tube of a double pipe heat exchanger with diameter ‘d’. For a fixed mass flow rate, the tube side heat transfer co-efficient for turbulent flow conditions is proportional to_____________________?

• 1. d0.8
• 2. d-0.2
• 3. d-1
• 4. d-1.8

Question: For a perfectly transparent surface (like gases), the____________________?

• 1. Absorptivity = 0
• 2. Transmissivity = 1
• 3. Reflectivity = 0
• 4. All A, B & C

Question: If air (a non-condensing gas) is present in a condensing vapor stream, it will ______________ the condensation rate of vapor?

• 1. Increase
• 2. Decrease
• 3. Not affect
• 4. Increase the condensing film co-efficient as well as