Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 201910 AprilEvening Shift
Exam
JEE Main
Year
2019
Date
10 April
Shift
Evening Shift
Subject
Physics
Chapter
Mechanical Properties of Fluids

JEE Main 2019 · 10 April · Evening Shift · Physics · Mechanical Properties of Fluids

Water from a tap emerges vertically downwards with an initial speed...

Water from a tap emerges vertically downwards with an initial speed of 1.0ms−11.0m{s}^{- 1} . The cross −- sectional area of the tap is 10−4m2{10}^{- 4}{m}^{2} . Assume that the pressure is constant throughout the stream of water and that the flow is streamlined. The cross −- sectional area of the stream, 0.15m0.15m below the tap would be:
(Take g=10ms−2g = 10m{s}^{- 2} )

Options

  1. A1×10−5m21 \times {10}^{- 5}{m}^{2}
  2. B5×10−4m25 \times {10}^{- 4}{m}^{2}
  3. C2×10−5m22 \times {10}^{- 5}{m}^{2}
  4. D5×10−5m25 \times {10}^{- 5}{m}^{2}

Correct answer

D. 5×10−5m25 \times {10}^{- 5}{m}^{2}

Step-by-step solution

Velocity of water after falling through distance 0.15m0.15m is
v2=u2+2as{v}^{2} = {u}^{2} + 2as
=1+2×10×0.15= 1 + 2 \times 10 \times 0.15
v2=4{v}^{2} = 4
v=2m/sv = 2m / s
From equation of continuity
A1v1=A2v2{A}_{1}{v}_{1} = {A}_{2}{v}_{2}
A2=10−4×12=5×10−5m2{A}_{2} = \dfrac{{10}^{- 4} \times 1}{2} = 5 \times {10}^{- 5}{m}^{2}
Practice Mechanical Properties of Fluids on Quantrex Academy →

More from Mechanical Properties of Fluids

Passage: A container of height 2 m, length 2 m and breadth 1 m is made of insulating… JEE Advanced 2026A liquid of density 600 kg/m ^3 flowing steadily in a tube of varying cross-section. The… JEE Main 2026A spherical liquid drop of radius R acquires the terminal velocity v_1 when falls through… JEE Main 2026A cylindrical vessel of 40 cm radius is completely filled with water and its capacity is… JEE Main 2026Eight mercury drops, each of radius r , coalesce to form a bigger drop. The surface… JEE Main 2026A water spray gun is attached to a hose of cross sectional area 30 cm ^2 . The gun… JEE Main 2026The surface tension of a soap solution is 3.5 × 10^ -2 N/m. The work required to increase… JEE Main 2026The surface tension of a soap bubble is 0.03 N/m. The work done in increasing the… JEE Main 2026 Full Mechanical Properties of Fluids list All JEE Main PYQs