ANS:B - Archaeology

No answer description is available. 

ANS:D - iostream.h

No answer description is available. Let's discuss.

ANS:A - degree of the curve

Da = (D *C) ÷ 200.

Where
Da= deflection angle,
D= degree of curve,
C = Length of Chord. Using 30m arc or chord definition the degree of curve D = 1718.9/R.
And the Rankine's deflection angle for the chord of length S is S*1718.9/R.
Hence, option A is correct.

ANS:B -

No answer description is available.

ANS:C - large quantity of solvent is required to extract the solute.

When the solvent dissolves very little solute, it means that the solubility of the solute in the solvent is low. In such a scenario:

• Solvent of low latent heat of vaporization should be used: Using a solvent with a low latent heat of vaporization would facilitate the removal of the solvent from the solution during the separation process. Since only a small amount of solute is dissolved, using a solvent with a low latent heat of vaporization would make the evaporation of the solvent more efficient and require less energy.

ANS:A - 2

To determine the new head of the centrifugal pump when its speed is halved, we can use the affinity laws that relate the pump performance to changes in speed. The affinity laws relevant for this scenario are:

1. Head Affinity Law: The head developed by a centrifugal pump is proportional to the square of the speed (RPM). H1H2=(N1N2)2\frac{H_1}{H_2} = \left( \frac{N_1}{N_2} \right)^2H2​H1​​=(N2​N1​​)2
2. Flow Affinity Law: The flow rate through a centrifugal pump is directly proportional to the speed (RPM). Q1Q2=N1N2\frac{Q_1}{Q_2} = \frac{N_1}{N_2}Q2​Q1​​=N2​N1​​

• Initial head, H1=8H_1 = 8H1​=8 metres
• Initial speed, N1=800N_1 = 800N1​=800 rpm
• New speed, N2=8002=400N_2 = \frac{800}{2} = 400N2​=2800​=400 rpm (since speed is halved)

Conclusion:

ANS:A - Ahmedabad

Urban-20 (U20) program is being organized in Ahmedabad.

ANS:A - sand to cement ratio.

The correct answer is: sand to cement ratio.

Explanation:

Explanation of Sand to Cement Ratio

1. Importance of the Ratio

• Strength: The sand to cement ratio affects the compressive strength of concrete. A balanced ratio ensures adequate strength and durability.
• Workability: This ratio influences the workability of the mix, affecting how easily the concrete can be mixed, placed, and finished.

2. Common Ratios

• Concrete Mixes: Typical sand to cement ratios for concrete can range from 2:1 to 4:1, depending on the desired strength and application.
• Mortar Mixes: For masonry mortars, the ratio might range from 3:1 to 6:1, again varying based on the requirements of the project.

3. Effects of Different Ratios

• Higher Sand Content: Increasing the sand content relative to cement can enhance workability but may reduce overall strength and increase shrinkage.
• Higher Cement Content: A higher cement content usually leads to increased strength but can make the mix less workable and more prone to cracking if not managed properly.

4. Factors Influencing the Choice of Ratio

• Type of Structure: The intended use of the concrete (e.g., foundations, slabs, walls) often dictates the optimal sand to cement ratio.
• Environmental Conditions: Conditions such as temperature, humidity, and exposure to elements can influence the chosen ratio for optimal performance.
• Material Quality: The quality and type of sand and cement can also affect the ideal ratio for a specific application.

5. Practical Considerations

• Mix Design: Proper mix design is essential to ensure the right balance between sand and cement for achieving the desired strength, durability, and workability.
• Testing: Regular testing of concrete samples is advisable to ensure compliance with strength requirements based on the selected sand to cement ratio.

Summary

ANS:A - New Delhi

Asian Wrestling Championships 2023 is to take place between March 28 to April 2nd in New Delhi.

ANS:C - 15%

The members of the EU have agreed to implement a 15% tax rate on large multinational corporations.