please give me the ans. of following mcq
A nozzle is a device which:
(A) Increase pressure & reduce kinetic energy
(B) Decreases pressure & increases kinetic energy
(C) Reduces both pressure & kinetic energy
(D) Increases both pressure & kinetic energy
Answer Posted / newgradengineer
|-------
FR1=A1V1 | \ FR2 =A2V2
----->| | ----->
P1V1=nRT1 | / P2V2 = nRT2
|-------
FR = flow rate
since this is a close system, FR1 = FR2
A1V1 = A2V2
-> A1/A2 = V2/V1 Since A1/A2 > 1 --> V2/V1 > 1 or V2>V1
Kinetic Energy = 1/2*m*v^2. Higher velocity gives higher
kinetic energy
We have P1V1 = nRT1 and P2V2 = nRT2
Assume there is no change in T
---> P1V1 = P2V2
---> P1/P2 = V2/V1 since V2/V1 > 1 --> P1/P2 >1 or P1>P2
(B) decreases pressure and increases kinetic energy is the
correct answer
Is This Answer Correct ? | 12 Yes | 0 No |
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