Explore topic-wise MCQs in BITSAT.

This section includes 125 Mcqs, each offering curated multiple-choice questions to sharpen your BITSAT knowledge and support exam preparation. Choose a topic below to get started.

51.

In a two-dimensional steady flow field, in a certain region of the x-y plane, the velocity component in the x-direction is given by \({v_x} = {x^2}\)and the density varies as \(\rho = \frac{1}{x}\) Which of the following is a valid expression for the velocity component in the y-direction, vy?

A. \({v_y} = - x/y\)
B. \({v_y} = x/y\)
C. \({v_y} = - xy\)
D. \({v_y} = xy\)
Answer» D. \({v_y} = xy\)
52.

For a forced vortex flow in an open tank, which of the following statements is correct?

A. Fall of liquid level at the centre = 0.5 × rise of liquid level at the ends
B. Fall of liquid level at the centre = 0.95 × rise of liquid level at the ends
C. Fall of liquid level at the centre = 0.98 × rise of liquid level at the ends
D. Fall of liquid level at the centre = rise of liquid level at the ends
Answer» E.
53.

For a two dimensional potential flow, the velocity potential is given by : ϕ = 4x(3y - 4) The numerical value of stream function at the point (2, 3) is

A. 10 Units
B. 20 Units
C. 18 Units
D. 16 Units
Answer» D. 16 Units
54.

In a two-dimensional incompressible steady flow, the velocity component u = Aex is obtained. What is the order component v of velocity?

A. v = Aexy
B. v = Aey
C. v = -Aexy + f(x)
D. v = -Aeyx + f(y)
Answer» D. v = -Aeyx + f(y)
55.

A stream function is given by ψ = 4x – 3y. The resultant velocity at any point is

A. 7.81 units/s
B. 7 units/s
C. 3.5 units/s
D. 5 units/s
Answer» E.
56.

Consider the following remarks pertaining to the irrotational flow:1. The Laplace equation of stream function \(\frac{{{\delta ^2}{\rm{\Psi }}}}{{\delta {x^2}}} + \frac{{{\delta ^2}{\rm{\Psi }}}}{{\delta {y^2}}} = 0\) must be satisfied for the flow to be potential.2. The Laplace equation for the velocitypotential \(\frac{{{\delta ^2}{\rm{\varphi }}}}{{\delta {x^2}}} + \frac{{{\delta ^2}{\rm{\varphi }}}}{{\delta {y^2}}} = 0\) must be satisfied to fulfil the orate . of mass conservation i.e continuity equation..Which of the above statements is/are correct?

A. 1 only
B. Both 1 and 2
C. 2 only
D. Neither 1 or 2
Answer» C. 2 only
57.

If in a flow field \(\frac{P}{\gamma} + \frac{v^2}{2g} + z \) = constant between any two points, flow must be

A. Steady, compressible and irrotational
B. Unsteady, incompressible and irrotational
C. Steady, incompressible and irrotational
D. Steady, compressible and along a steam line
Answer» D. Steady, compressible and along a steam line
58.

Consider a velocity field \({\rm{\vec V}} = {\rm{K}}\left( {{\rm{y\hat i}} + {\rm{x\hat k}}} \right)\), where K is a constant. The vorticity, ΩZ, is

A. - K
B. K
C. - K /2
D. K /2
Answer» B. K
59.

A curve that is everywhere tangent to the instantaneous local velocity vector, is

A. Streak line
B. Path line
C. Normal line
D. Stream line
Answer» E.
60.

A vertical circular cylinder is filled with water and then rotated about its vertical axis at a constant speed such that half the liquid spills out from the open top. At that instant, the pressure at the centre of the bottom should be

A. atmospheric pressure
B. sub-atmospheric pressure
C. one fourth of original value
D. more than atmospheric pressure
Answer» B. sub-atmospheric pressure
61.

A 2-D flow field is defined as \(\vec V = \vec ix - \vec jy\). The equation of the streamline passing through the point (1, 1) is

A. xy -1 = 0
B. xy + 1 = 0
C. xy + 2 = 0
D. xy - 2 = 0
Answer» B. xy + 1 = 0
62.

______________ is an imaginary line drawn through a flowing fluid in such a way that the tangent to it at any point gives the direction of the velocity of flow at that point.

A. Vortex line
B. Stream line
C. Streak line
D. Path line
Answer» C. Streak line
63.

For a steady flow, the values of all fluid properties at any fixed point

A. change with location
B. do not change with time
C. do not change with location
D. change with time
Answer» C. do not change with location
64.

A grid obtained by drawing a series of equipotential lines and stream lines is called _______.

A. equipotential net /
B. stream net
C. flow net
D. viscosity potential function
Answer» D. viscosity potential function
65.

A continuity equation for two dimensional compressible flow is given by:

A. \(\frac{{\partial u}}{{\partial x}}\; + \;\frac{{\partial v}}{{\partial x}}\left( {\rho uv} \right)\; = 0\)
B. \(u\frac{{\partial u}}{{\partial x}}\; + v\frac{{\partial v}}{{\partial x}}\; = 0 \)
C. \(\frac{{\partial \left( {\rho u} \right)}}{{\partial x}}\; + \;\frac{{\partial \left( {\rho v} \right)}}{{\partial y}} = 0\)
D. \(\frac{{\partial u}}{{\partial x}}\; + \;\frac{{\partial v}}{{\partial x}}\; = 0 \)
Answer» D. \(\frac{{\partial u}}{{\partial x}}\; + \;\frac{{\partial v}}{{\partial x}}\; = 0 \)
66.

A current meter is a device used for measuring

A. velocity
B. viscosity
C. current
D. pressure
Answer» B. viscosity
67.

Δψ between two streamlines represents___ (where ψ is a stream function)

A. velocity
B. discharge
C. head
D. pressure
Answer» C. head
68.

If the velocity of fluid does NOT change with respect to time, the flow is said to be:

A. non uniform flow
B. interflow
C. steady flow
D. cross flow
Answer» D. cross flow
69.

If the velocity potential function ϕ =5 (x2 – y2), the velocity components at the points (4, 5) will be

A. u = -35, v = 40
B. u = -40, v = 55
C. u = -40, v = 50
D. u = 40, v = -50
Answer» D. u = 40, v = -50
70.

A cylindrical vessel with closed bottom and open top is 0.9 m in diameter. What is the rotational speed about its vertical axis (with closed bottom below and open top above) when the contained incompressible fluid will rise 0.5 m at the inner circumference of the vessel and a space of 0.4 m diameter have no fluid thereon? Take g = 10 m/s2

A. 650 rpm
B. 600 rpm
C. 580 rpm
D. 96 rpm
Answer» E.
71.

A steady incompressible flow field is given by u = 2x2 + y2 and v = -4xy. The convective acceleration, along x - direction at point (1, 2) is

A. 6 units
B. 24 units
C. -8 units
D. -24 units
Answer» D. -24 units
72.

If an incompressible fluid enters a pipe with a velocity of 4 cm/s and moves out with a velocity of 2 cm/s, calculate the cross sectional area of the inlet if the diameter of the pipe at the outlet is 7 cm.

A. 154 sq.cm.
B. 20 sq.cm.
C. 14 sq.cm.
D. 7 sq.cm.
Answer» C. 14 sq.cm.
73.

A one dimensional flow is one which _______

A. Is uniform
B. Is steady uniform
C. Takes place in straight lines
D. Involves zero transverse components of flow
Answer» E.
74.

If 60000 cum of water flows per min through a pipe of diameter 3 m and if this pipe reduces to a 1.5 m diameter, what is the ratio of the velocities in these pipes?

A. 0.25
B. 0.3
C. 0.03
D. 0.05
E. 0.02
Answer» B. 0.3
75.

Ψ = 3x2 – y3 represents a stream function in a two – dimensional flow. The velocity component in ‘x’ direction at the point (1, 3) is:

A. – 24 m/s
B. 4 m/s
C. 27 m/s
D. 31.5 m/s
Answer» D. 31.5 m/s
76.

A fluid flowing through a pipe of diameter 450 mm with velocity 3 m/s is divided into two pipes of diameters 300 mm and 200 mm. The velocity of flow in 300 mm diameter pipe is 2.5 m/s, then the velocity of flow through 200 mm diameter pipe will be

A. 2.5 m/s
B. 5.55 m/s
C. 7.25 m/s
D. 9.56 m/s
Answer» E.
77.

In a free vortex, the flow is:

A. rotational
B. irrotational
C. rotational or irrotational
D. neither rotational or irrotational
Answer» C. rotational or irrotational
78.

A constant discharge passing through a conical pipe is an example of

A. steady uniform flow
B. steady non-uniform flow
C. unsteady uniform flow
D. unsteady non-uniform flow
Answer» C. unsteady uniform flow
79.

A duct of rectangular cross-section 600 mm × 400 mm carries 90 m3/min of air having density of 1.2 kg/m3. When the quantity of air in both cases is same, the equivalent diameter of a circular duct will be nearly

A. 0.86 m
B. 0.76 m
C. 0.64 m
D. 0.54 m
Answer» E.
80.

A flow whose stream line is represented by a curve, is called _______.

A. One - dimensional flow
B. Three dimensional flow
C. Two - dimensional flow
D. Four - dimensional flow
Answer» D. Four - dimensional flow
81.

If the velocity, pressure, density, etc., change at a point with respect to time, the flow is called

A. uniform
B. compressible
C. unsteady
D. incompressible
Answer» D. incompressible
82.

A path line:

A. cannot be defined for fluid flows
B. indicates fluid velocity
C. indicates path taken by a fluid element
D. indicates local fluid direction
Answer» D. indicates local fluid direction
83.

In a Lagrangian system, the position of a fluid particle in a flow is described as

A. unsteady and one-dimensional
B. steady and two-dimensional
C. steady and one-dimensional
D. unsteady and two-dimensional
Answer» C. steady and one-dimensional
84.

A velocity field is given as \(\vec V = \;Axy\hat i - \;Byzt\hat j\;\)where A and B are constants. x, y, z are in metre and t is in seconds. Which of the following is true of this flow field?

A. Steady and 3 - dimensional
B. Unsteady and 2 – dimensional
C. Steady and 2 – dimensional
D. Unsteady and 3 – dimensional
Answer» E.
85.

If fluid properties in a flow are constant with space at any instant of time, the flow is termed as:​

A. uniform
B. non - uniform
C. steady
D. unsteady
Answer» B. non - uniform
86.

In the case of a steady uniform flow of a fluid, the acceleration is:

A. zero
B. 1
C. any value greater than 1
D. Infinity
Answer» B. 1
87.

In virtual work equation some forces are neglected. Select the most appropriate answer from the following:

A. Reaction of a rough surface on a body which rolls on it without slipping.
B. Reaction of any smooth surface with which the body is in contact.
C. Reaction at a point or on an axis, fixed in space, around which a body is constrained to turn.
D. All of the above
Answer» E.
88.

For an incompressible flow field, \(\vec V\) , which one of the following conditions must be satisfied?

A. \(\nabla \cdot \vec V = 0\)
B. \(\nabla \times \vec V = 0\)
C. \(\left( {\vec V \cdot \nabla } \right)\vec V = 0\)
D. \(\frac{{\partial \vec V}}{{\partial t}} + \left( {\vec V \cdot \nabla } \right)\vec V = 0\)
Answer» B. \(\nabla \times \vec V = 0\)
89.

In a flow field, the streamlines and equipotential lines

A. are parallel
B. cut at any angle
C. are orthogonal everywhere in the flow field
D. cut orthogonally except at the stagnation points
Answer» E.
90.

A fluid flow field is given by \(U = 2xyi + yzj - \left( {2yz + \frac{{{z^2}}}{2}} \right)k.\)1. The flow is viscous.2. The flow is steady3. The flow is incompressible.4. The magnitude of the total velocity vector at a point (1, 4, 3) is nearest to 27 units.Which of the above statements are correct?

A. 1 and 3 only
B. 1 and 4 only
C. 2 and 3 only
D. 2 and 4 only
Answer» D. 2 and 4 only
91.

A static fluid can have

A. Positive normal stress and zero shear stress
B. Zero normal stress and non-zero shear stress
C. Non-zero normal stress and non-zero shear stress
D. Positive normal stress and non-zero shear stress
Answer» B. Zero normal stress and non-zero shear stress
92.

Both free vortex and forced vortex can be expressed mathematically in terms of tangential velocity V at the corresponding radius r. Choose the correct combination Free vortexForced vortex1V = r × constVr = const2V2 × r = constV = r × const3V × r = const.V2 = r × const4V × r = const.V = r × const

A. 1
B. 2
C. 3
D. 4
Answer» E.
93.

If the total acceleration of fluid flow is always zero, then it is:

A. unsteady and uniform flow
B. steady and uniform flow
C. steady but non-uniform flow
D. unsteady and non-uniform flow
Answer» C. steady but non-uniform flow
94.

A flow net is a graphical representation of streamlines and equipotential lines such that these lines

A. Intersect each other at various different angles forming irregular shaped nets
B. Intersect each other orthogonally forming curvilinear squares
C. Indicate the direction but not magnitude of vector
D. Indicate the direction and magnitude of vector
Answer» C. Indicate the direction but not magnitude of vector
95.

A liquid of density 1200 kg/m3 is flowing steadily through a tube of varying cross section as shown below. The cross section at point A is 1 cm2 and at B is 20 mm2. The points A and B are in the same horizontal plane. The speed of liquid at point A is 10 cm/sec. The difference of pressure at A and B is

A. 100 Pa
B. 170 Pa
C. 144 Pa
D. 180 Pa
Answer» D. 180 Pa
96.

A 2-D flow field is defined as\(\vec V = \hat ix - \hat jy\)The equation of stream line passing through the point (1,1)

A. xy - 1 = 0
B. x - y = 0
C. 2x + 2y = 0
D. xy = 0
Answer» B. x - y = 0
97.

For a two-dimensional incompressible flow field given by \(\vec u = A\left( {x\hat i - y\hat j} \right)\), where A > 0, which one of the following statements is FALSE?

A. It satisfies continuity equation.
B. It is unidirectional when x → 0 and y → ∞
C. Its streamlines are given by x = y .
D. It is irrotational.
Answer» D. It is irrotational.
98.

If the fluid velocity for a potential flow is given by V(x,y) = u(x,y)i + v(x,y)ĵ with usual notations, then the slope of the potential line at (x,y) is

A. \(\frac{v}{u}\)
B. \(- \frac{u}{v}\)
C. \(\frac{{{v^2}}}{{{u^2}}}\)
D. \(\frac{u}{v}\)
Answer» C. \(\frac{{{v^2}}}{{{u^2}}}\)
99.

A stream function is given by (x2 – y2). The potential function of the flow will be

A. 2xy + f(x)
B. 2(x2 – y2)
C. -2xy + constant
D. 2xy + f(y)
Answer» D. 2xy + f(y)
100.

Consider the following equations:(a) A1v1 = A2v2(b) \(\frac{{\partial u}}{{\partial x}} + \frac{{\partial v}}{{\partial y}} = 0\)(c) \(\mathop \smallint \limits_{\rm{s}} {\rm{pV}}.{\rm{dA}} + \frac{\partial }{{\partial {\rm{t}}}}\mathop \smallint \limits_{\rm{v}} {\rm{pdV}} = 0\)(d) \(\frac{1}{r}\;\frac{\partial }{{\partial r}}\left( {r{v_r}} \right) + \frac{\partial }{{\partial z}}\left( {{v_z}} \right) = 0\)Which of the above equations are forms of continuity equations? (Where u, v are velocities and V is volume)

A. Only 1
B. 1 and 2
C. 2 and 3
D. 3 and 4
Answer» C. 2 and 3