ANS:C - Once a reference variable has been defined to refer to a particular variable it cannot refer to any other variable.

No answer description is available. Let's discuss.

ANS:B - the diaphragm is placed between the eyepiece and the objective but nearer to the later

Here, option B should be" the diaphragm is placed between the eyepiece and objective but farther from later".

ANS:C - seriously overload the circuit

No answer description is available.

ANS:C - > 8:1

In a moderately sized packed absorption tower, channeling occurs when the flow of the gas or liquid becomes unevenly distributed across the cross-section of the tower. This uneven distribution can lead to reduced contact between the gas and liquid phases and decreased efficiency of the absorption process. To minimize channeling, it is important to ensure uniform distribution of the gas and liquid flows across the packed bed. One way to achieve this is by maintaining an appropriate ratio of tower diameter to packing diameter. The recommended ratio of tower diameter to packing diameter to minimize channeling is typically greater than 8:1. A tower with a larger diameter relative to the size of the packing particles allows for better distribution of the gas and liquid flows, reducing the likelihood of channeling. Therefore, the correct option is > 8:1.

ANS:A - increases in the downstream direction.

When we discuss "increases in the downstream direction" in the context of flow velocity in a pipeline, we are referring to a specific scenario that applies to supersonic flow conditions. Here’s a more detailed explanation:

1. Supersonic Flow: Supersonic flow occurs when the flow velocity (v) within the pipeline exceeds the speed of sound (Mach 1). In such cases, the behavior of the flow differs significantly from subsonic flow (where v < Mach 1).
2. Expansion Waves: In supersonic flow, when there is an increase in the cross-sectional area of the pipeline (such as from a nozzle exit or a sudden expansion), expansion waves are generated. These expansion waves travel downstream at the speed of sound relative to the flow velocity.
3. Effect on Velocity: As the expansion waves propagate downstream faster than the flow velocity itself, they effectively increase the flow area and allow the flow velocity to increase in the downstream direction. This is a fundamental aspect of supersonic flow behavior.
4. Nozzle Example: For instance, consider a converging-diverging nozzle used in supersonic flow applications (like in rocket engines or supersonic wind tunnels). As the flow exits the converging section into the diverging section, the flow expands and the area increases. This expansion causes the flow velocity to increase downstream in the diverging section beyond the sonic throat (where the flow velocity reaches Mach 1).
5. Characteristics: Unlike subsonic flow, where velocity typically decreases due to frictional losses and conservation of mass principles, supersonic flow experiences increasing velocity due to the expansion waves moving faster than the flow itself.

ANS:B - Home Ministry

The Union Home Ministry has released the survey of the Registrar General and Census Commissioner's Office and said that Jharkhand itself is witnessing the highest number of child marriages. Jharkhand and West Bengal topped the worst state list in terms of child marriage.

ANS:C - decreases

With an increase in temperature, the equilibrium constant at constant pressure (Kp) for the oxidation of sulfur dioxide increases. With an increase in temperature, the equilibrium constant at constant pressure (Kp) for the oxidation of sulfur dioxide increases due to the following reasons:

1. Endothermic Reaction:

• Reaction Type:
  • The oxidation of sulfur dioxide (SO₂) to sulfur trioxide (SO₃) is generally an endothermic reaction. According to Le Chatelier's principle, increasing the temperature shifts the equilibrium to favor the formation of products.

2. Le Chatelier's Principle:

• Equilibrium Shift:
  • When the temperature increases, the system responds by shifting the equilibrium position to the right, leading to a higher concentration of products (in this case, SO₃). This shift results in an increase in the equilibrium constant (Kp).

3. Mathematical Relationship:

• Van't Hoff Equation:
  • The relationship between temperature and equilibrium constant can be described by the Van't Hoff equation, which shows that for endothermic reactions, an increase in temperature leads to an increase in Kp:
  dln⁡KdT=ΔHreactionRT2\frac{d \ln K}{dT} = \frac{\Delta H_{reaction}}{RT^2}dTdlnK​=RT2ΔHreaction​​
  • Here, ΔHreaction\Delta H_{reaction}ΔHreaction​ is positive for endothermic reactions, indicating that Kp increases with temperature.

Summary:

ANS:D - Ministry of Commerce and Industry

The Department for Promotion of Industry and Internal Trade (DPIIT), Ministry of Commerce and Industry has notified the establishment of the Credit Guarantee Scheme for Startups (CGSS).

ANS:C - H₂S₂O₇

The chemical formula of oleum is H₂S₂O₇. The chemical formula of oleum is H₂S₂O₇, and here’s an explanation of its composition and significance:

Composition:

1. Sulfuric Acid Derivative:
   • Oleum is a solution of sulfur trioxide (SO₃) in sulfuric acid (H₂SO₄). It can be seen as a concentrated form of sulfuric acid containing extra sulfur trioxide.
2. Molecular Structure:
   • The formula H₂S₂O₇ indicates that oleum consists of two sulfur atoms, seven oxygen atoms, and two hydrogen atoms. This structure reflects its acidic nature and high sulfur content.

Properties:

1. Highly Corrosive:
   • Oleum is a strong acid and is highly corrosive, capable of reacting violently with water and organic materials.
2. Viscous Liquid:
   • It appears as a thick, oily liquid, which can vary in concentration depending on the amount of dissolved SO₃.

Production:

1. Manufacturing Process:
   • Oleum is typically produced during the contact process for sulfuric acid production, where sulfur dioxide is oxidized to sulfur trioxide, which is then absorbed in existing sulfuric acid.

Applications:

1. Industrial Use:
   • Oleum is used in the production of sulfuric acid, in chemical synthesis, and as a dehydrating agent in various chemical processes.
2. Sulfonation:
   • It is used in the sulfonation of organic compounds, important in the manufacturing of detergents, dyes, and pharmaceuticals.

Summary:

ANS:A - Reserve Bank of India

The Reserve Bank of India (RBI) released a concept note on the Central Bank Digital Currency (CBDC).