Water flows through two identical tubes A and B. A volume V₀ of water passes through the tube A and 2V₀ through B in a given time. Which of the following may be correct?
(a) Flow in both the tubes are steady.
(b) Flow in both the tubes are turbulent.
(c) Flow is steady in A but turbulent in B.
(d) Flow is steady in B but turbulent in A.
Answers
Answer ⇒
Explanation ⇒ Given conditions,
Volume passes at A = V₀ and Volume passes at B = 2V₀.
As we can see that double the volume passes in B at the same time, the velocity of flow in B will be twice that of A (Since, volume rate of flow is directly proportional to velocity).
Now, we know that there are an limit of velocity after which the steady flow may turn into turbulent flow. If the Reynolds, number is greater than 1500, then the flow is turbulant and below it is steady.
Now, this answer will be based on the chances or you can say probability.
If the velocities in both the tubes are below the limit of turbulant flow, then option (a) may be correct.
If the velocities in both the tubes are above this limit then option (b) may be true.
If the velocity in A is less than the limit of Reynolds number but in B more than the limit then option (c) may be correct.
Now, Flow in B is steady and turbulant in A is not possible, since volume rate of flow is morer in B and less in A. Hence, Option (d). is incorect.
Hence, Option (a)., (b)., and (c). is only correct.
Hope it helps.
Answer:
If the velocities in both the tubes are below the limit of turbulant flow, then option (a) may be correct.
If the velocities in both the tubes are above this limit then option (b) may be true.
If the velocity in A is less than the limit of Reynolds number but in B more than the limit then option (c) may be correct.
Now, Flow in B is steady and turbulant in A is not possible, since volume rate of flow is morer in B and less in A. Hence, Option (d). is incorect.
Hence, Option (a)., (b)., and (c). is only correct.