ANS:A - disapproved

No answer description is available. 

ANS:A - True

True, the programmer tells the compiler to include the preprocessor when compiling.

ANS:D - All of these.

Refractory metals are a class of metals that are extraordinarily resistant to heat and wear.

ANS:D - range reduction by factor of 10 is employed

When volt ratio box is used to reduce range, the advantage of open-circuit measurement is lost.

ANS:C - ECD₁₆

Convert to decimal, subtract and change the result to hexadecimal.

ANS:B - >1

The selectivity of the solvent used in solvent extraction should be greater than 1. Selectivity in solvent extraction refers to the preference of the solvent for one component over another in the mixture being separated. A selectivity value greater than 1 indicates that the solvent has a greater affinity for one component compared to the other. This property is desirable because it helps to achieve efficient separation of the desired component from the mixture. Therefore, the correct answer is > 1.

ANS:C - 2

In the Stokes' law range, which applies to the motion of spherical particles in a stationary fluid at low Reynolds numbers, the ratio of wall drag to form drag is approximately 1.

Explanation:

1. Stokes' Law Range:
   • Stokes' law applies when the Reynolds number (ReReRe) is very low (typically Re<1Re < 1Re<1). In this range, the drag force FDF_DFD​ experienced by the particle is primarily due to viscous forces and can be given by: FD=6πμRvF_D = 6 \pi \mu R vFD​=6πμRv where:
     • μ\muμ is the dynamic viscosity of the fluid,
     • RRR is the radius of the spherical particle,
     • vvv is the velocity of the particle relative to the fluid.
2. Components of Drag:
   • Wall Drag: This is the drag force due to the shear stress at the surface of the particle interacting with the fluid. For a spherical particle in Stokes' flow, the wall drag contributes significantly to the total drag force.
   • Form Drag: Form drag arises due to the pressure difference between the front and rear of the particle as it moves through the fluid. In the Stokes' regime, the form drag is much smaller compared to the wall drag because the flow around the particle is largely laminar and streamlined.
3. Ratio of Wall Drag to Form Drag:
   • The ratio of wall drag to form drag is approximately 1 in the Stokes' law range. This means that the wall drag dominates the total drag force experienced by the spherical particle moving through the fluid.

Conclusion:

ANS:D - Kerala

Dangerous 'Norovirus' was found in Kerala.

ANS:A - Himachal Pradesh

Himachal Pradesh celebrated its 53rd Foundation Day on January 25.

ANS:A - Gujarat

The 30th National Children's Science Congress will be organized in Gujarat from 27 to 31 January.