Engineering Questions with Answers - Multiple Choice Questions
MCQs on Deflection of Continuous Beam
The maximum negative bending moment in fixed beam carrying udl occurs at ________
a) Mid span
b) 1/3 of the span
d) Half of the span
Explanation: In case of fixed beam subjected to gravity loads maximum hogging or negative bending moment develops at the supports. At centre, the maximum bending moment is reduced.
A fixed beam of the uniform section is carrying a point load at the centre, if the moment of inertia of the middle half portion is reduced to half its previous value, then the fixed end moments will ______
b) Remains constant
d) Change their direction
Explanation: The flexural rigidity value is reduced in middle half portion of the second case fixed end moments which have developed in a beam section will be increases.
In propped cantilevers, the prop reaction is 3/8 wl.
Explanation: In propped cantilever beam net deflection at fixed end is zero therefore Rl3/3EI = wl4/8EI
A propped cantilever beam carrying total load “W” distributed evenly over its entire length calculate the vertical force required in the prop.
a) 3/4 W
c) 5/8 W
d) 3/8 W
Explanation: Therefore Total load on beam = W = wl
Rl3/3EI = Wl3/ 8EI.
R = 3W/8.
The vertical force required at the prop is 3W/8.
_____ is a small opening made in the bottom or sides of a tank.
Explanation: An orifice is defined as a small opening of any cross sections such as circular, square, triangular& rectangular etc. made in the walls or the bottom of a tank containing liquid in it through which the liquid flows.
A mouthpiece is a short length of a pipe which is not more than __________ times its diameter.
c) 1 -2
Explanation: A mouth piece is defined as a short length of a pipe which is not more than two or three times its diameter, fitted to an orifice of same diameter provided especially in a tank containing liquid.
The section which has a minimum cross sectional are in a flow is known as _______
a) Vena contracta
d) Upstream edge
Explanation: The section of the jet, at which the flow in a liquid has a minimum cross sectional area, is known as vena contracta. This is due to the fact that liquid particles do not change their directions abruptly.
Bell mouthed orifices can be categorised in according to ___________
c) Shape of upstream
d) Nature of discharge
Explanation: The orifices are classified on the basis of their size, shape, shape of upstream edge and discharge conditions. According to shape of the upstream edge, the orifices are classified as sharp edged orifice and Bell mouthed orifice.
Which of the following is not a hydraulic coefficient?
a) Coefficient of contraction
b) Coefficient of discharge
c) Coefficient of viscosity
d) Coefficient of velocity
Explanation: Coefficient of viscosity can be defined as the shear stress required producing unit rate of angular deformation. It is also called as dynamic viscosity.
Theorotical velocity = _______
Explanation: The coefficient of velocity the ratio of actual velocity of the liquid to the theoretical velocity. Theoretical velocity = (2gh)1/2.
Where h = liquid head above the centre of orifice.
The value of Cv varies _______ to ________
a) 0.95 – 0.99
b) 0.93 – 0.95
c) 0.97 – 1
d) 0.94 – 0.96
Explanation: The value of coefficient of velocity (Cv) vary from 0.95 to 0.99 for different orifices depending on shape, size of the orifices and the head under which floor takes place
The Cv taken for sharp edged orifice generally is _________
Explanation: The Cv taken for sharp edged orifice generally is 0.98.
|Value For Sharp edged orifice||Hydraulic coefficient|
Coeffecient of discharge varies from ___________ to __________
a) 0.64 to 0.68
b) 0.61 to 0.65
c) 0.63 to 0.67
d) 0.67 to 0.7
Explanation: Coefficient of discharge is defined as the ratio between actual discharge from an orifice and its theoretical discharge. It varies from 0.61 to 0.65.Generally, the value for Cd = 0.62 Sir sharp edged orifice.
The relation between hydraulic coefficients is Cd = Cc × Cv.
Explanation: Cd = Qa / Qth
But Qa = ac V =(Cc a) × Cv × (2gh)1/2.
Qth = a Vth
Cd = Qa Qth = Cc a × Cv (2gh)1/2/a × (2gh)1/2.
Cd = Cc × Cv.
Calculate the actual velocity of jet if the coefficient of velocity is 0.97. The head of water on the orifice of diameter 2 cm is 6 m.
a) 11 m/s
b) 12 m/s
c) 10.5 m/s
d) 13 m/s
Explanation: We know that quotient of velocity the ratio of actual velocity to theoretical velocity. The actual velocity of jet Va = Cv × (2gh)1/2.
Va = 0.97 (2× 9.81 ×6 )1/2.
Va = 10.5 m/s.