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Saturday, 31 October

JEE Main 2022 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 28 July 2022, Shift 2, Physics Q7

Question 7 of 90 in this shift, Physics question 7 of 30, Section A.

Consider a cylindrical tank of radius 1m is filled with water. The top surface of water is at 15 m from the bottom of the cylinder. There is a hole on the wall of cylinder at a height of 5 m from the bottom. A force of 5×1055\times10^5 N is applied an the top surface of water using a piston. The speed of ifflux from the hole will be : (given atmospheric pressure PA\mathrm{P_A} = 1.01×1051.01\times10^5 Pa , density of water ρw\rho_\mathrm{w} = 1000 kg/m31000\ \mathrm{kg/m^3} and gravitational acceleration g = 10 m/s210\ \mathrm{m/s^2} )

The figure, in words

Cylindrical tank of water with a piston on top pushed by a force of 5 x 10^5 N; water depth 15 m; hole in the wall at 5 m above the bottom (10 m of water above the hole marked) with an arrow showing outflow.
  1. (1)11.6 m/s
  2. (2)10.8 m/s
  3. (3)17.8 m/sOfficial answer
  4. (4)14.4 m/s

Official answer

Option 3

NTA final key.

Chapter
Mechanical Properties of Fluids
Topic
Fluid Dynamics
Idea tested
Torricelli's Law of Efflux

Same idea in other shifts

Asked 3× in all
  1. 27 Jun 2022, Shift 1 · Q59The area of cross-section of a large tank is 0.5 m20.5\ \mathrm{m^2}. It has a narrow opening near the bottom having area of cross-section…MediumNumerical value
  2. 18 Mar 2021, Shift 2 · Q28Consider a water tank as shown in the figure. It’s cross-sectional area is 0.4 m2^2. The tank has an opening B near the bottom whose…MediumNumerical valueHas a figure

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.