Fluid Mechanics

Q. A two-dimensional water jet strikes a fixed two-dimensional plate at 30° to the normal to the plate. This causes the jet to split into two streams in which the ratio of larger discharge to smaller discharge is

1. 14.0
2. 3.0
3. 2.0
4. 1.0

Q. A horizontal water jet with a velocity of 10 m/s and cross-sectional area of 10 mm${}^2$ strikes a flat plate held normal to the flow direction. The density of water is 1000kg/$m^3$. The total force on the plate due to the jet is

1. 100N
2. 10 N
3. 1 N
4. 0.1 N

Q. A horizontal jet of water with its cross-sectional area of 0.0028 m${}^2$ hits a fixed vertical plate with a velocity of 5 m/s. After impact the jet splits symmetrically in a plane parallel to the plane of the plate. The force of impact (in N) of the jet on the plate is

1. 90
2. 80
3. 70
4. 60

Q. A jet of oil of relative density 0.8 and of area 0.02 $m^2$ issues at 10 m/s. If it strikes normally on a stationary plate, the force exerted on the plate is

1. 1906 N
2. 15606 N
3. 1600 N
4. 19581 N

Q. A horizontal jet strikes a frictionless vertical plate (the plan view is shown in the figure). It is then divided into two parts, as shown in the figure. If the impact loss is neglected, what is the value of $\theta$ ?

1. 15${}^{\circ }$
2. 30${}^{\circ }$
3. 45${}^{\circ }$
4. 60${}^{\circ }$

Q. The discharge over a broad crested weir is maximum when the depth of flow is

1. $\frac{H}{3}$
2. $\frac{2H}{3}$
3. $\frac{H}{2}$
4. $\frac{2H}{5}$

Q. A submerged weir is one in which the water level on the down stream side of the weir is:

1. Just at the crest level
2. Below the crest level
3. Above crest level
4. At same elevation as water surface on upstream

Q.

Among weirs used in open flow metrology, critical depth of the flow is the relevant criterion in:

1. Broad-crested weir

2. Cippoletti weir

3. Parabolic weir

4. Sharp-crested weir

Q. A Cipolletti weir discharges water with the head of water over the crest being 250 mm. If the head due to velocity of approach is 0.01 m, What will be the excess percentage of flow, when corrected for velocity of approach as compared to when not so corrected?

1. 3.2%
2. 4.2%
3. 5.3%
4. 6.3%

Q.

For accurate flow measurement in open channels, an arrangement for aeration under the nappe is necessary when the weir used is

1. Contracted rectangular

2. Suppressed rectangular

3. Submerged contracted rectangular

4. Triangular