ANS:C - 2341

No answer description is available. 

ANS:D - Both A and B.

No answer description is available. Let's discuss.

ANS:C - radius of the curve

The curve is designated by the radius of curve and angle subtended by the chord of a particular length (30m). Also called the degree of curve. Here only answer C is correct. So answer C is correct. According to me, the Design of the curve is done on the basis of Radius and Degree of the curve. Design of curve R = 1718 * V^2/D.

ANS:D -

No answer description is available.

ANS:D - truck/tunnel.

A truck/tunnel dryer, also known as a tunnel kiln or a tunnel dryer, is a type of continuous drying system commonly used in industrial settings for drying various materials including refractories. Here's how it generally works:

1. Tunnel Structure: It consists of a long tunnel-like structure with a conveyor belt system running through it. The tunnel is divided into different zones, each with its own temperature and airflow controls.
2. Conveyor Belt: The refractory materials to be dried are loaded onto trays or placed directly on a conveyor belt. The conveyor belt moves continuously through the tunnel, carrying the materials along its length.
3. Heating System: Heat is applied to the tunnel through various means such as gas burners, electric heaters, or steam coils. The temperature settings can be adjusted to meet the specific drying requirements of the refractories.
4. Air Circulation: Proper airflow is maintained within the tunnel to ensure even drying of the materials. This is often achieved through the use of fans or blowers that circulate heated air throughout the tunnel.
5. Controlled Environment: The drying process is typically conducted in a controlled environment to optimize drying efficiency and ensure the quality of the dried refractories.
6. Continuous Operation: One of the key advantages of a truck/tunnel dryer is its ability to handle large volumes of material continuously. As the conveyor belt moves through the tunnel, new batches of material can be loaded at one end while dried material is unloaded at the other end, allowing for a continuous production process.

ANS:A - V²

In turbulent flow in a pipe, the head loss hfh_fhf​ is generally proportional to the square of the velocity VVV of the fluid. Therefore, the correct answer is: V2V^2V2

Explanation:

1. Head Loss in Turbulent Flow:
   • In turbulent flow through a pipe, head loss hfh_fhf​ is caused by frictional effects between the flowing fluid and the pipe wall.
   • The Darcy-Weisbach equation is commonly used to calculate head loss in turbulent flow: hf=f⋅LD⋅V22gh_f = f \cdot \frac{L}{D} \cdot \frac{V^2}{2g}hf​=f⋅DL​⋅2gV2​ where:
     • fff is the Darcy-Weisbach friction factor,
     • LLL is the length of the pipe,
     • DDD is the diameter of the pipe,
     • VVV is the velocity of the fluid,
     • ggg is the acceleration due to gravity.
2. Proportionality to Velocity:
   • From the Darcy-Weisbach equation, it can be seen that hfh_fhf​ is directly proportional to V2V^2V2.
   • This means that doubling the velocity will result in a fourfold increase in head loss due to friction.
3. Other Options:
   • 1V2\frac{1}{V^2}V21​ and 1V\frac{1}{V}V1​ are inversely proportional to velocity and do not represent the correct relationship for head loss in turbulent flow.
   • VVV alone is not the correct proportional term for head loss; it is V2V^2V2 that represents the frictional losses associated with turbulent flow in a pipe.

Conclusion:

ANS:C - both (a) & (b)

The correct answer is: Neither (a) nor (b). Styrene butadiene rubber (SBR) is produced from the polymerization of styrene and butadiene. Ethyl alcohol and ethylene are not starting materials for SBR. Ethyl alcohol, also known as ethanol, is a volatile, flammable, colorless liquid with the chemical formula C2H5OHC_2H_5OHC2​H5​OH. It is commonly used in alcoholic beverages, as a fuel or fuel additive, and in various industrial applications. Here are some key points about ethyl alcohol:

Properties

• Chemical Formula: C2H5OHC_2H_5OHC2​H5​OH
• Molecular Weight: 46.07 g/mol
• Boiling Point: 78.37 °C (173.07 °F)
• Melting Point: -114.1 °C (-173.4 °F)
• Density: 0.789 g/cm³ at 20 °C

Uses

1. Beverages: Ethanol is the active ingredient in alcoholic drinks. It is produced through the fermentation of sugars by yeast.
2. Fuel: Ethanol can be used as a biofuel or fuel additive. It is often blended with gasoline to create ethanol-blended fuels like E10 (10% ethanol, 90% gasoline).
3. Solvent: It is widely used as a solvent in the pharmaceutical, cosmetics, and chemical industries due to its ability to dissolve a wide range of substances.
4. Antiseptic: Ethanol is used in hand sanitizers and disinfectants because of its antibacterial properties.
5. Industrial Applications: It is used in the manufacture of personal care products, paints, varnishes, and perfumes.

Production

1. Fermentation: This is the most common method for producing ethanol for beverages and some industrial uses. Sugars from crops like corn, sugarcane, or other biomass are fermented by yeast.
2. Ethylene Hydration: Ethanol can also be synthesized from ethylene (a petrochemical) through a process called acid-catalyzed hydration. This is primarily used for industrial ethanol production.

Chemical Reactions

• Combustion: Ethanol burns in air to produce carbon dioxide, water, and heat. C2H5OH+3O2→2CO2+3H2O+energyC_2H_5OH + 3O_2 \rightarrow 2CO_2 + 3H_2O + \text{energy}C2​H5​OH+3O2​→2CO2​+3H2​O+energy
• Dehydration: Ethanol can be dehydrated to produce ethylene. C2H5OH→acidC2H4+H2OC_2H_5OH \xrightarrow{\text{acid}} C_2H_4 + H_2OC2​H5​OHacid​C2​H4​+H2​O
• Oxidation: Ethanol can be oxidized to produce acetaldehyde and further to acetic acid. C2H5OH+[O]→CH3CHO+H2OC_2H_5OH + [O] \rightarrow CH_3CHO + H_2OC2​H5​OH+[O]→CH3​CHO+H2​O

Properties

• Chemical Formula: C2H4C_2H_4C2​H4​
• Molecular Weight: 28.05 g/mol
• Boiling Point: -103.7 °C (-154.7 °F)
• Melting Point: -169.4 °C (-272.9 °F)
• Density: 1.178 kg/m³ at 15 °C

Uses

1. Polymer Production: Ethylene is a primary feedstock for the production of polyethylene, the most common plastic. It is also used to produce other polymers like polyvinyl chloride (PVC) and polystyrene.
2. Chemical Intermediate: Ethylene is a key raw material in the manufacture of chemicals like ethylene oxide, ethylene glycol, and ethanol.
3. Ripening Agent: In agriculture, ethylene is used as a plant hormone to ripen fruits such as bananas and tomatoes.
4. Industrial Applications: Ethylene is used in the production of antifreeze, solvents, and detergents.

Production

1. Natural Gas: Methane, ethane, and propane can be cracked to produce ethylene.
2. Crude Oil: Naphtha, a fraction of crude oil, can be used as a feedstock in steam cracking.

Chemical Reactions

• Polymerization: Ethylene molecules can join together to form polyethylene, a widely used plastic. nC2H4→−(C2H4)n−nC_2H_4 \rightarrow -(C_2H_4)_n-nC2​H4​→−(C2​H4​)n​−
• Oxidation: Ethylene can be oxidized to produce ethylene oxide, a precursor to ethylene glycol (used in antifreeze and polyester production). C2H4+12O2→C2H4OC_2H_4 + \frac{1}{2}O_2 \rightarrow C_2H_4OC2​H4​+21​O2​→C2​H4​O
• Hydration: Ethylene can react with water in the presence of a catalyst to produce ethanol. C2H4+H2O→C2H5OHC_2H_4 + H_2O \rightarrow C_2H_5OHC2​H4​+H2​O→C2​H5​OH

Industrial Importance

ANS:A - Kanpur

PM inaugurated the 356 Km long Bina-Panki Multiproduct Pipeline Project; which connects the Bina refinery in MP to Panki in Kanpur.

ANS:D - New Delhi

Union Home Minister Amit Shah chaired 3rd meeting of the Apex Level Committee of the Narco Coordination Center in New Delhi

ANS:D - None of these

The correct answer is: None of these. All the options listed (polyisoprene, neoprene, and nitrile-butadiene) are elastomers. Here’s a brief overview of each:

1. Polyisoprene: This is the synthetic version of natural rubber and is known for its excellent resilience, tensile strength, and elasticity.
2. Neoprene: This is a synthetic rubber also known as polychloroprene. It is resistant to oil, chemicals, and weathering, making it suitable for a variety of applications, including wetsuits and gaskets.
3. Nitrile-butadiene: Commonly known as NBR or nitrile rubber, it is resistant to oils and fuels, making it ideal for use in the automotive and aeronautical industries.