SSC JE Mechanical Engineering 24th Jan 2018 Shift-2

the velocity of sound is reached

the boundary layer comes to rest

the cross-section of a channel is reduced

the pressure reaches a minimum

requires that Newton’s second law of motion be satisfied at every point in fluid

relates the momentum per unit volume for two points on a streamline

expresses the relation between energy and work

relates mass rate of flow along a streamline

flow occurs in a zig zag way

Reynolds number lies between 2000 and to 3000 for pipes

Newton’s law of viscosity is of importance

None of these

horizontal straight line

linear downward

approximately hyperbola

parabola with its vertex at the opening

to maintain pressure difference

to increase discharge

to increase velocity

None of these

$$\frac{\partial u}{\partial x} + \frac{\partial v}{\partial y} + \frac{\partial w}{\partial z} = 0$$

$$\frac{\partial u}{\partial x} - \frac{\partial v}{\partial y} - \frac{\partial w}{\partial z} = 0$$

$$\frac{\partial u}{\partial x} + \frac{\partial v}{\partial y} + \frac{\partial w}{\partial x} = 1$$

$$\frac{\partial u}{\partial x} + \frac{\partial v}{\partial y} + \frac{\partial w}{\partial z} = u.v.w$$

one dimensional flow

two dimensional flow

three dimensional flow

multi-dimensional flow

Only A

Only E

Only C

None of these

$$\frac{L}{D} = \frac{l_1}{d_1} + \frac{l_2}{d_2} + \frac{l_3}{d_3} + .....$$

$$\frac{L}{D^2} = \frac{l_1}{d_1^2} + \frac{l_2}{d_2^2} + \frac{l_3}{d_3^2} + .....$$

$$\frac{L}{D^3} = \frac{l_1}{d_1^3} + \frac{l_2}{d_2^3} + \frac{l_3}{d_3^3} + .....$$

$$\frac{L}{D^5} = \frac{l_1}{d_1^5} + \frac{l_2}{d_2^5} + \frac{l_3}{d_3^5} + .....$$

at every point the velocity vector is identical, in magnitude and direction, for any given instant

the flow is steady

discharge through a pipe is constant

conditions do not change with time at any point