wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Two pipes of same length and radii in the ratio 1:2 are connected in series. A liquid flows through them in streamlined condition. If the pressure across the two extreme ends of the combination in 1 m of water, the pressure difference across the first pipe is

A
9.4 m of water
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
4.9 m of water
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
0.49 m of water
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
0.94 m of water
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution

The correct option is D 0.94 m of water
Since pipes are of same length,
l1=l2=l
r1r2=12
r1=r and r2=2r


In series combination, the flow rate through tubes will be same, pressure difference across ends will be equal to sum of pressure difference across individual pipe.
ΔP=ΔP1+ΔP2........(i)
Q=πr4ΔP18ηl=π(2r)4ΔP28ηl........(ii)
From Eq. (ii),
ΔP1ΔP2=(2r)4r4=16
ΔP1=16ΔP2
Given: Pressure difference across ends (ΔP) is equivalent to 1 m water head
1=ΔP1+ΔP116
ΔP1=1617=0.94 m
Hence pressure difference across first tube is equivalent to 0.94 m water head.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
Join BYJU'S Learning Program
CrossIcon