Class 11 Physics | Fluid Dynamics | #16 Solved Example-7 on Fluid Dynamics | For JEE & NEET

[@gigachadkartik]

Pitot tube and Venturimeter had a kid.

[@sourabhmishra2656]

Dear Sir, could you please elaborate how you wrote P(a)-P(b)=h*[rho Hg-rho]*g in 2:57 ? How is the difference in densities taken ?

[@physicsgalaxyworld]

by using Pascal's law at a level in one liquid pressure must be same... so if we move from one tube to other from same level we write gain or loss in pressure and by the equation we get it...

[@PrinceVegeta001]

@@physicsgalaxyworld But sir shouldn't it be Rho-Rho(hg)??

[@aSKv3051]

Sir are you saying that at 3:05 at point B the mercury is almost touching the venturimeter? why because you didn't consider the water between venturimeter and the mercury as mentioned in the diagram

[@physicsgalaxyworld]

No. Thats not required as water above both the tubes of venturimeter above the mercury level of right part is filled with water so it is not required to be considered above this level...

[@aSKv3051]

Physics Galaxy Thanks for the explanation. I got it sir now

[@arjitarora9399]

Sir in right side tube also water is inside then why we not take pressure due to water in right tube...

[@nidhishrivastava8705]

goat without a doubt!

[@prabhatkumarverma200]

Does pressure in a moving liquid at a same level remains same according to pascal law....

[@arulyanasokan1658]

Sir, the same question is given in HCV (Q33) and the ans is 1.97cm

[@punisher4422]

Exactly

[@Nerdface727]

value of g is taken 9.8 in hcv i think

[@vishwajeetchoudhary8264]

​@@Nerdface727then height will be even more not less

[@aamreenfatima4853]

17 Oct 2020

[@SoumilSahu]

i didn't follow what you did at 2:50

[@physicsgalaxyworld]

We have calculated the pressure difference due to the difference in level of the two liquids in U tube...

[@riteshuppal1357]

This topic is given in NCERT 10.4.2 There is no concept given like "difference of densities"...they have used the result P1-P2=rho(of medium inside the u-tube)*h*g...even HC verma has the same!...So what SHOULD WE FOLLOW!!???

[@saketshrivastava7169]

Ritesh Uppal you should see previous 4 video of physics galaxy Ashish sir has explained it clearly

[@riteshuppal1357]

Saket Shrivastava Thanks for your suggestion 😀...but before replying i hope you must have gone through ncert and hcv..the reference i gave.!?..i have seen all his videos in sequence..

[@drvksau]

In NCERT, note that they have attached a manometer in the shape of a U-tube. This implies that the fluid occupying the space in the U-tube where mercury has gone down (point A to the surface of Hg) is a gas. So, due to the very light nature of gas, the difference in density can be approximated as the density of mercury. But, if, as in this question, the U-tube has a liquid, ignoring the liquid density is imprudent, and we should follow the method sir uses.

[@lucifrr895]

@@drvksau thanks bhai mere ko yahi samjh nahi aa raha tha