41. The velocity in m/s at a point in a two-dimensional flow is given as ^→V = 2î + 3ĵ . The equation of the stream line passing through the point is
    

1. 1. 3dx – 2dy = 0

   
   
   

   2. 2x + 3y = 0

   
   
   

   3. 3dx + 2dy = 0

   
   
   

   4. 3xy = 6

   
   
   

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1. View Hint View Answer Discuss in Forum

   ^→V = 2î + 3ĵ
   

   	u	=	dx
   	v		dy

   
   

   	2	=	dx
   	3		dy

   
   ∴ 3dx = 2dy
   ⇒ 3dx – 2dy = 0

   Correct Option: A

   ^→V = 2î + 3ĵ
   

   	u	=	dx
   	v		dy

   
   

   	2	=	dx
   	3		dy

   
   ∴ 3dx = 2dy
   ⇒ 3dx – 2dy = 0

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42. The allowable net positive suction head (NPSH) for a pump provided by the manufacturer for a flow of 0.05 m³ /s is 3.3m. The temperature of water is 30°C (vapour pressure head absolute = 0.44 m), atmospheric pressure is 100 kPa absolute and the head loss from the reservoir to pump is 0.3 N-m/N. The maximum height of the pump above the suction reservoir is
    

1. 1. 10.19 m

   
   
   

   2. 6.89 m

   
   
   

   3. 6.15 m

   
   
   

   4. 2.86 m

   
   
   

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1. View Hint View Answer Discuss in Forum

   Head loss , hL = 0.3	Nm	= 0.3 m of water
   	N

   
   NPSH = H_atm – H_v – h_s – h_L
   

   3.3 =	100 × 103	- 0.44 - hs - 0.3
   	1000 × 9.81

   
   ⇒ h_s = 6.15 m
   

   Correct Option: C

   Head loss , hL = 0.3	Nm	= 0.3 m of water
   	N

   
   NPSH = H_atm – H_v – h_s – h_L
   

   3.3 =	100 × 103	- 0.44 - hs - 0.3
   	1000 × 9.81

   
   ⇒ h_s = 6.15 m
   

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43. The height of a hydraulic jump in the stilling pool of 1.25 scale model was observed to the 10 cm. The corresponding prototype height of the jump is
    

1. 1. not determinable from the data given

   
   
   

   2. 2.5 m

   
   
   

   3. 0.5 m

   
   
   

   4. 0.1 m

   
   
   

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1. View Hint View Answer Discuss in Forum

   L_r = 1.25
   

   Lr =	hm
   	hp

   
   

   	1	=	10
   	25		hp

   
   ⇒ h_p = 250 cm = 2.5 m

   Correct Option: B

   L_r = 1.25
   

   Lr =	hm
   	hp

   
   

   	1	=	10
   	25		hp

   
   ⇒ h_p = 250 cm = 2.5 m

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44. The reading of differential manometer of a Venturimeter, placed at 45° to the horizontal is 11 cm. If the Venturimeter is turned to horizonal position, the manometer reading will be.
    

1. 1. zero
      

   
   
   

   2. 	11	cm
      	√2

      
      

   
   
   

   3. 11
      

   
   
   

   4. 11 √2

   
   
   

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1. View Hint View Answer Discuss in Forum

   The indication of pipe does not affect the recading of the manometer, since it measure pressure difference between two points and will not change with orientation.

   Correct Option: C

   The indication of pipe does not affect the recading of the manometer, since it measure pressure difference between two points and will not change with orientation.

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45. Which one of the following equations represents the downstream profile of Ogee spillway with vertical upstream face {(x,y) are the co-ordinates of the point on the downstream profile with origin at the crust of the raliway and H_d is the design head

1. 1. y	= 0.5		x		1.85
      Hd			Hx

   
   
   

   2. y	= -0.5		x		1 /1.85
      Hd			Hd

   
   
   

   3. y	= -2.0		x		1.85
      Hd			Hd

   
   
   

   4. y	= -2.0		x		1 / 1.85
      Hd			Hd

   
   
   

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1. View Hint View Answer Discuss in Forum

   The downstream profile of the ogee creat may confirm to the following equation : x^1.85 = K₂ H_d^0.85 y₂

   Correct Option: B

   The downstream profile of the ogee creat may confirm to the following equation : x^1.85 = K₂ H_d^0.85 y₂

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