Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Properties of Matter question

2025 · 22 Jan · Shift 2 · Q61
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /JEE Main
  3. /Physics
  4. /Properties of Matter
  5. /2025 · 22 Jan · Shift 2 · Q61

Properties of Matter question

2025 · 22 Jan · Shift 2 · Q61

JEE MainPhysicsProperties of MatterMCQ+4 / −1
JEE Main 2025 (Online) 22nd January Evening Shift Physics - Properties of Matter Question 27 English A tube of length LLL is shown in the figure. The radius of cross section at the point (1)(1)(1) is 2 cm and at the point (2) is 1 cm , respectively. If the velocity of water entering at point (1) is 2 m/s2 \mathrm{~m} / \mathrm{s}2 m/s, then velocity of water leaving the point (2) will be
  1. A
    4 m/s
  2. B
    6 m/s
  3. C
    2 m/s
  4. D
    8 m/s
View written solutionFree

Correct answer: D

  1. Use equation of continuity for incompressible flow:

A1v1=A2v2A_1 v_1 = A_2 v_2A1​v1​=A2​v2​

where:

  • A1=πr12A_1 = \pi r_1^2A1​=πr12​
  • A2=πr22A_2 = \pi r_2^2A2​=πr22​
  • v1=2 m/sv_1 = 2\,\text{m/s}v1​=2m/s
  1. Given radii:

r1=2 cm,r2=1 cmr_1 = 2\,\text{cm}, \qquad r_2 = 1\,\text{cm}r1​=2cm,r2​=1cm

So,

A1=π(2)2=4πA_1 = \pi (2)^2 = 4\piA1​=π(2)2=4π A2=π(1)2=πA_2 = \pi (1)^2 = \piA2​=π(1)2=π

  1. Substitute into continuity equation:

A1v1=A2v2A_1 v_1 = A_2 v_2A1​v1​=A2​v2​

4π⋅2=π⋅v24\pi \cdot 2 = \pi \cdot v_24π⋅2=π⋅v2​

8π=πv28\pi = \pi v_28π=πv2​

v2=8 m/sv_2 = 8\,\text{m/s}v2​=8m/s

  1. Therefore, the velocity of water at point (2) is:

8 m/s\boxed{8\,\text{m/s}}8m/s​

  1. Check options:
  • A: 444 m/s ❌
  • B: 666 m/s ❌
  • C: 222 m/s ❌
  • D: 888 m/s ✅

Hence, the correct option is D.

PreviousNext

More from Properties of Matter

  • A small rigid spherical ball of mass M is dropped in a long vertical tube containing glycerine. The velocity of the ball becomes constant after some time. If the density of glycerine is half of the density of the ball, then the viscous…2025 · MCQ
  • Given below are two statements: Statement I: The hot water flows faster than cold water Statement II: Soap water has higher surface tension as compared to fresh water. In the light above statements, choose the correct answer from the…2025 · MCQ
  • A massless spring gets elongated by amount x1​ under a tension of 5 N . Its elongation is x2​ under the tension of 7 N . For the elongation of (5x1​−2x2​), the tension in the spring will be,2025 · MCQ
  • Water flows in a horizontal pipe whose one end is closed with a valve. The reading of the pressure gauge attached to the pipe is P1​. The reading of the pressure gauge falls to P2​ when the valve is opened. The speed of water flowing…2025 · MCQ
  • An air bubble of radius 1.0 mm is observed at a depth 20 cm below the free surface of a liquid having surface tension 0.095 J/m2 and density 103 kg/m3. The difference between pressure inside…2025 · Numerical
  • An air bubble of radius 0.1 cm lies at a depth of 20 cm below the free surface of a liquid of density 1000 kg/m3. If the pressure inside the bubble is 2100 N/m2 greater than the atmospheric…2025 · MCQ
  • The amount of work done to break a big water drop of radius ' R ' into 27 small drops of equal radius is 10 J . The work done required to break the same big drop into 64 small drops of equal radius will be2025 · MCQ
  • The increase in pressure required to decrease the volume of a water sample by 0.2% is P×105Nm−2. Bulk modulus of water is 2.15×109Nm−2. The value of P is ​…2025 · Numerical