# A retaining wall of height 8 m retains dry sand. In the initial state, the soil is loose and has a void ratio of 0.5,γd = 17.8 kN/m3 and φ = 300. Subsequently, the backfill is compacted to a state where void ratio is 0.4, γd=18.8 kN/m3 and φ = 350. The ratio of initial passive thrust to the final passive thrust, according to Rankine’s earth pressure theory, is

1.  0.38

2.  0.64

3.  0.77

4.  1.55

4

0.77

Explanation :
No Explanation available for this question

# A velocity field is given aswhere x and y are in metres. The acceleration of the a fluid particle at (x,y) = (1,1) in the x direction is

1.  0 m/s2

2.  5.00 m/s2

3.  6.00 m/s2

4.  8.48 m/s2

4

8.48 m/s2

Explanation :
No Explanation available for this question

# A thin flat plate 0.5 m x 0.7 m in size settles in a large tank of water with a terminal velocity of 0.12 m/s. The co-efficient of drag CD = 1.328/√RLfor a laminar boundary layer and CD = 0.072/(RL )1/5 for a turbulent boundary layer,where RL,is the plate Reynolds number. Assume μ=10-3N-s/m2 and ρ=1000kg/m3.The submerged weight of the plate is:

1.  0.0115N

2.  0.0118N

3.  0.0231N

4.  0.0376N

4

0.0115N

Explanation :
No Explanation available for this question

# A fire protection system is supplied from a water tower with a bent pipe as shown in the figure. The pipe friction f is 0.03. Ignoring all minor losses, the maximum discharge, Q in the pipe is

1.  31.7 lit/sec

2.  24.0 lit/sec

3.  15.9 lit/sec

4.  12.0 lit/sec

4

24.0 lit/sec

Explanation :
No Explanation available for this question

# A steady flow occurs in an open channel with lateral inflow of q m3/s per unit width as shown in the figure. The mass conservation equation is

1.  ∂q/∂x=0

2.  ∂Q/∂x=0

3.  ∂Q/∂x-q=0

4.  ∂Q/∂x+q=0

4

∂Q/∂x=0

Explanation :
No Explanation available for this question

# A steep wide rectangular channel takes off from a reservoir having an elevation of 101.2 m. At the entrance, the bottom elevation of the channel is 100 m. If the slope of the channel is increased by 4%, the discharge per unit length in the channel will be

1.  2.24 m2/s

2.  higher than 2.24 m2/s by 4%

3.  higher than 2.24 m2/s by 2%

4.  choked

4

higher than 2.24 m2/s by 2\%

Explanation :
No Explanation available for this question

# The velocity in m/s at a point in a two-dimensional flow is given as.The equation of the stream line passing through the point is

1.  3dx-2dy=0

2.  2x+3y=0

3.  3dx+2dy=0

4.  3xy=6

4

3dx-2dy=0

Explanation :
No Explanation available for this question

# For the differential equation,f(x,y)(dy/dx)+g(x,y)=0 to be exact

1.  af/ay=ag/ax

2.  af/ax=ag/ay

3.  f=g

4.  a2f/ax2=a2g/ay2

4

af/ay=ag/ax

Explanation :
No Explanation available for this question

# The allowable net positive suction head (NPSH) for a pump provided by the manufacturer for a flow of 0.05 m3/s is 3.3 m. The temperature of water is 300 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.  10.19 m

2.  6.89 m

3.  6.15 m

4.  2.86 m

4

6.15 m

Explanation :
No Explanation available for this question

# If A and B are two matrices and if AB exists, then BA exists

1.  only if A has as many rows as B has columns

2.  only if both A and B are square matrices

3.  only if A and B are skew matrices

4.  only if both A and B are symmetric

4