FLUID-MECHANICS-QUIZ-5

FLUID MECHANICS QUIZ-5

Dear Readers,

As per analysis for previous years, it has been observed that students preparing for NEET find Physics out of all the sections to be complex to handle and the majority of them are not able to comprehend the reason behind it. This problem arises especially because these aspirants appearing for the examination are more inclined to have a keen interest in Biology due to their medical background. 

Furthermore, sections such as Physics are dominantly based on theories, laws, numerical in comparison to a section of Biology which is more of fact-based, life sciences, and includes substantial explanations. By using the table given below, you easily and directly access to the topics and respective links of MCQs. Moreover, to make learning smooth and efficient, all the questions come with their supportive solutions to make utilization of time even more productive. Students will be covered for all their studies as the topics are available from basics to even the most advanced. 

Q1. Water rises in a capillary tube to a height. Choose the false statement regarding rise from the following

•  On the surface of Jupiter, height will be less than h
•  In a lift, moving up with constant acceleration, height is less than h
•  On the surface of the moon, the height is more than h
•  In a lift moving down with constant acceleration height is less than h

Solution

Q2.If a ball of steel density ρ=7.8 g cm^-3 attains a terminal velocity of 10cms^-1 when falling in a tank of water (coefficient of viscosity ɳ_water=8.5×10^-4 Pa-s) then its terminal velocity in glycerine (ρ=12 g cm^-3,ɳ=13.2 Pa-s) would be nearly

•  1.06×10^-5 cms^-1
•  6.25×10^-4 cms^-1
•  6.45×10^-4 cms^-1
•  1.5×10^-5 cms^-1

Solution

Q3.  A cylinder containing water upto a height of 25 cm has a hole of cross-section 1/4 cm² in its bottom. It is counterpoised in a balance. What is the initial change in the balancing weight when water begins to flow out

•  Increase of 12.5 gm-wt
•  Increase of 6.25 gm-wt
•  Decrease of 12.5 gm-wt
•  Decrease of 6.25 gm-wt

Solution

Q4. The height of the dam, in an hydroelectric power station is 10 m. In order to generate 1 MW of electric power, the mass of water (in kg) that must fall per second on the blades of the turbine is

•  10⁶
•  10⁵
•  10³
•  10⁴

Solution

Q5.A water film is formed between two parallel wires of 10 cm length. The distance of 0.5 cm between the wires is increased by 1 mm. Which will be the work done? (Surface tension of water =72 Nm^-1

•  288 erg
•  144 erg
•  72 erg
•  36 erg

Solution
 

Q6. Two metal spheres are falling through a liquid of density 2×10³ kg/m³ with the same uniform speed. The material density of sphere 1 and sphere 2 are 8×10³ kg/m³ and 11×10³ kg/m³ respectively. The ratio of their radii is

•  11/8
•  √(11/8)
• 3/2
•  √(3/2)

Solution

Q7.A sphere of radius R is gently dropped into liquid of viscosity ɳ in a vertical uniform tube. It attains a terminal velocity v. Another sphere of radius 2R when dropped into the same liquid, will attains its terminal velocity

•  v
•  2v
•  4v
•  9v

Solution

Q8.Two cylinders of same cross-section and length L but made of two material of densities ρ₁ and ρ₂ (in CGS units) are cemented together to form a cylinder of length2 L. If the combination floats in water with a length L/2 above the surface of water and ρ₁< ρ_{2, then}

•  ρ₁>1
•  ρ₁< 3/4
•  ρ₁>1/2
•  ρ₁>3/4

Solution

Q9.A block of steel of size 5 cm×5 cm×5 cm is weighed in water. If the relative density of steel is 7, its apparent weight is

•  6×5×5×5 gf
•  4×4×4×7 gf
•  5×5×5×7 gf
•  4×4×4×6 gf

Solution

Q10. A block of aluminium of mass 1 kg and volume 3.6×10^-4 m³ is suspended from a string and then completely immersed in a container of water. The decrease in tension in the string after immersion is

•  9.8 N
•  6.2 N
•  3.6 N
• 1.0

Solution