Engineering Questions with Answers - Multiple Choice Questions
Strength of Materials MCQs Definition of Torque
1 - Question
Torque is __________ moment.
a) Twisting
b) Shear
c) Bending
d) Couple
View Answer
Answer: a
Explanation: A cylindrical shaft is subjected to twisting moment or torque when a force is acting on the member tangentially at some radius in a plane of its cross section.
2 - Question
Twisting moment is a product of __________ and the radius.
a) Direction
b) Velocity
c) Force
d) Acceleration
View Answer
Answer: c
Explanation: Twisting moment will be equal to the product of force and radius. When a shaft is subjected to a twisting moment, every cross section of the shaft will surely experience shear stress.
3 - Question
Torsion is denoted by __________
a) R
b) Q
c) T
d) N
View Answer
Answer: c
Explanation: If the moment is applied in a plane perpendicular to the longitudinal axis of the beam (or) shaft it will be subjected to torsion. Torsion is represented or denoted by T.
4 - Question
The SI units for torsion is __________
a) N m
b) N
c) N/m
d) m
View Answer
Answer: a
Explanation: As torsion is a product of perpendicular force and radius, the units will be N m.
Torque is also known as torsion or twisting moment or turning moment.
5 - Question
_____________ torsion is produced when twisting couple coincides with the axis of the shaft.
a) Exact
b) Pure
c) Nominal
d) Mild
View Answer
Answer: b
Explanation: When a member is subjected to the equal and opposite twisting moment at its ends, then the member is said to be subjected under pure torsion. Pure Torsion is often produced when the axis of the twisting couple coincides with the axis of the shaft.
6 - Question
Which of the following is known as Re-entrant mouthpiece?
a) External Mouthpiece
b) Convergent Mouthpiece
c) Internal Mouthpiece
d) Cylindrical Mouthpiece
View Answer
Answer: c
Explanation: According to the position, mouthpieces are classified as an external mouthpiece and internal mouthpiece. If the tube projects inside the tank, it is called an internal mouthpiece or re-entrant or borda’s mouthpiece.
7 - Question
Micrometre contraction gauge is used to determine ___________
a) Cv
b) Cc
c) Ca
d) Cd
View Answer
Answer: b
Explanation: The coefficient of contraction may be determined experimentally by measuring the radius of jet as vena contact with the help of micro meter contraction gauge. This method is not accurate because it is very difficult to measure the correct radius of jet.
8 - Question
What is the general value for coefficient of contraction?
a) 0.64
b) 0.67
c) 0.66
d) 0.7
View Answer
Answer: a
Explanation: The ratio of the area of a jet at vena contracta to the area of orifice is known as the coefficient of contraction. The value of Cc varies from 0.61 to 0.69 for different orifices. Generally, for sharp edged orifice the value of Cc may be taken as 0. 64.
9 - Question
The Cd value for internal mouthpiece running free is __________
a) 0.6
b) 0.5
c) 0.7
d) 0.8
View Answer
Answer: b
Explanation: The Cd value for internal mouthpiece running free is 0.5.
Type Of Mouthpiece Value of Cd
External cylindrical mouthpiece 0.855
Internal mouthpiece running free 0.5
Internal mouthpiece running full 0.707
10 - Question
_______ is the velocity with which water reaches the notch or before it flows over it.
a) Velocity of contact
b) Velocity of moment
c) Velocity of approach
d) Velocity of head
View Answer
Answer: c
Explanation: The velocity of approach is defined as the velocity with which water reaches the notch or weir before it flows over it. This velocity of approach creates an additional head “ha” equal to Va2 / 2g and effect head over the notch is increased to H+ha.
11 - Question
Which of the following formula was proposed by Bazin?
a) m(2g)1/2×LH3/2
b) m(2g) 1/2×H3/2
c) n(2g) 1/2×LH4/3
d) n(2g)1/2×LH3/2
View Answer
Answer: a
Explanation: Bazin proposed the following formula for the discharge over rectangular weir:
Q = m(2g) 1/2× L H3/2.
Where m = 0.405 + 0.003/H.
12 - Question
For measuring low discharges _____________ notch is preferred.
a) Rectangular
b) Stepped
c) Trapezoidal
d) Triangular
View Answer
Answer: d
Explanation: A triangular notch is preferred to a rectangular notch due to
i. The nappe emerging from a triangular notch has the same shape for all heads. As such the value for the triangular notch is constant for all heads.
ii. The expression for discharge for right angle triangle law not is very simple.
13 - Question
Which of the following is also known as V notch?
a) Trapezoidal
b) Stepped
c) Triangular
d) Sharp edged
View Answer
Answer: c
Explanation: A triangular notch also called a v notch is of triangle shape with apex down. The expression of the discharge over triangular notch or weir is Q = 8/15 Cd (2g) 1/2 × H 5/2.
14 - Question
Calculate the discharge over rectangular Weir of 3 metres length under the head of 400mm.Use Francis formula.
a) 1.268 m3/s
b) 1.396 m3/s
c) 1.475 m3/s
d) 1.528 m3/s
View Answer
Answer: b
Explanation: Francis formula for discharge Q = 1.84 LH3/2.
Given L = 3m & H = 0.4m
Q = 1.84 × 3 × (0.4)3/2.
Q = 1.396 m3/s.
15 - Question
_____ converts mechanical energy into hydraulic energy.
a) Dynamo
b) Pump
c) Turbine
d) Generator
View Answer
Answer: b
Explanation: A pump is a mechanical device which converts the mechanical energy into hydraulic energy. The hydraulic energy is in the form of pressure energy. The pumps are generally used for lifting liquid from a lower level to a higher level.
16 - Question
Strength of Materials MCQs Torsion Equation
Torsional sectional modulus is also known as _________
a) Polar modulus
b) Sectional modulus
c) Torsion modulus
d) Torsional rigidity
View Answer
Answer: a
Explanation: The ratio of polar moment of inertia to radius of section is called Polar modulus or Torsional section modulus. Its units are mm3 or m3 (in SI).
17 - Question
________ is a measure of the strength of shaft in rotation.
a) Torsional modulus
b) Sectional modulus
c) Polar modulus
d) Torsional rigidity
View Answer
Answer: c
Explanation: The polar modulus is a measure of the strength of shaft in rotation. As the value of Polar modulus increases torsional strength increases.
18 - Question
What are the units of torsional rigidity?
a) Nmm2
b) N/mm
c) N-mm
d) N
View Answer
Answer: a
Explanation: The product of modulus of rigidity (C) and polar moment of inertia (J) is called torsional rigidity. Torsional rigidity is a torque that produces a twist of one radian in a shaft of unit length.
19 - Question
The angle of twist can be written as ________
a) TL/J
b) CJ/TL
c) TL/CJ
d) T/J
View Answer
Answer: c
Explanation: The angle of Twist = TL/CJ
Where T = Torque in Nm
L = Length of shaft
CJ = Torsional rigidity.
20 - Question
The power transmitted by shaft SI system is given by __________
a) 2πNT/60
b) 3πNT/60
c) 2πNT/45
d) NT/60 W
View Answer
Answer: a
Explanation: In SI system, Power (P) is measured in watts (W) ; P = 2πNT/60
Where T = Average Torque in N.m
N = rpm
= 2πNT/ 45 1 watt = 1 Joule/sec = 1N.m/s.
21 - Question
Area of catchment is measured in ___________
a) mm3
b) Km2
c) Km
d) mm
View Answer
Answer: b
Explanation: Catchment area can be defined as the area which contributes the surplus water present over it to the stream or river. It is an area which is responsible for maintaining flow in natural water bodies. It is expressed in square kilometres.
22 - Question
______ catchment area is a sum of free catchment area and intercepted catchment area.
a) Total
b) Additional
c) Combined
d) Overall
View Answer
Answer: c
Explanation: Combined catchment area is defined as the total catchment area which contributes the water in to stream or a tank. Combined Catchment area = Free catchment area + intercepted catchment area.
23 - Question
___________ has steep slopes and gives more run off.
a) Intercepted Catchment Area
b) Good Catchment Area
c) Combined Catchment Area
d) Average Catchment Area
View Answer
Answer: b
Explanation: Good catchment area consists of hills or rocky lands with steep slopes and little vegetation. It gives more run off.
24 - Question
How many number of rain gauge stations should be installed an area between 250 to 500 km2.
a) 2
b) 4
c) 3
d) 5
View Answer
Answer: c
Explanation: 3 number of rain gauge stations should be installed an area between 250 to 500 km2.
Area of Basin(Km2) Number of Rain gauge stations
< 125 1
125 – 250 2
250 – 500 3
25 - Question
Trend of rainfall can be studied from _______
a) Rainfall graphs
b) Rainfall records
c) Rainfall curves
d) Rainfall cumulatives
View Answer
Answer: b
Explanation: Rainfall records are useful for calculating run off over a basin. By using rainfall records estimate of design parameters of irrigation structures can be made. The maximum flow due to any storm can be calculated and predicted.
26 - Question
Estimation of run off “R” is 0.85P-30.48.
The above formula was coined by _____
a) Lacey
b) Darcy
c) Khosla
d) Ingli
View Answer
Answer: d
Explanation: Run off can be estimated by
R= 0.85P-30.48
Where R = annual runoff in mm
P = annual rainfall in mm.
27 - Question
Monsoon duration factor is denoted by ________
a) P
b) S
c) F
d) T
View Answer
Answer: c
Explanation: Monsoon duration factor is denoted by F.
Class of Monsoon Monsoon Duration Factor (F)
Very Short 0.5
Standard length 1.0
Very long 1.5
28 - Question
Runoff coefficient is denoted by _______
a) P
b) N
c) K
d) H
View Answer
Answer: c
Explanation: The runoff coefficient can be defined as the ratio of runoff to rainfall. Rainfall and runoff can be interrelated by runoff coefficient.
R = KP
K = R/P [K = is a runoff Coefficient depending on the surface of the catchment area].
29 - Question
_________ is a graph showing variations of discharge with time.
a) Rising limb graph
b) Crest graph
c) Hydraulic graph
d) Gauge graph
View Answer
Answer: c
Explanation: Hydrograph is a graph showing variations of discharge with time at a particular point of the stream. The hydrograph shows the time distribution of total run off at a point of measurement. Maximum flood discharge can also be calculated by using hydrograph.
30 - Question
Calculate the torque which a shaft of 300 mm diameter can safely transmit, if the shear stress is 48 N / mm2.
a) 356 kNm
b) 254 kNm
c) 332 kNm
d) 564 kNm
View Answer
Answer: b
Explanation: Given, the diameter of shaft D = 300 mm
Maximum shear stress fs = 48 N/mm2.
Torque = T = π/16 fs D3
= 254469004.9 Nmm
= 254 kNm.
31 - Question
Strength of Materials MCQs Shear Stress and Twisting Moment
The intensity of shear stress at a section is ______ to the distance of the section from the axis of the shaft.
a) Inversely proportional
b) Directly proportional
c) Equal
d) Parallel
View Answer
Answer: b
Explanation: The intensity of shear stress at a section is directly proportional to the distance of the section from axis of the shaft. The shear stress at a distance from the centre of the shaft is given by fs/R × r.
32 - Question
The shear stress is ____________ at the axis of the shaft.
a) Minimum
b) Maximum
c) Zero
d) Uniform
View Answer
Answer: c
Explanation: The shear stress is zero at the axis of the shaft and the shear stress is linearly increasing to the maximum value at the surface of the shaft.
33 - Question
The shear stress at the outer surface of hollow circular section is _________
a) Zero
b) Maximum
c) Minimum
d) Can’t determined
View Answer
Answer: b
Explanation: The shear stress in a hollow circular section varies from maximum at the outer surface to a minimum (but not zero) in the inner face. The minimum value should be greater than zero.
34 - Question
The hollow shaft will transmit greater _______ then the solid shaft of the same weight.
a) Bending moment
b) Shear stress
c) Torque
d) Sectional Modulus
View Answer
Answer: c
Explanation: For the same maximum shear stress, the average shear stress in a hollow shaft is greater than that in a solid shaft of the same area. Hence the hollow shaft will transmit greater torque than the solid shaft of the same weight.
35 - Question
The process of measurement of discharge and water level of a river is called _________
a) Meandering
b) River coursing
c) River gauging
d) Scouring
View Answer
Answer: c
Explanation: The process of measurement of discharge and water level of a river is known as river gauge. It helps in determining the characteristics of flow different times during the year.
36 - Question
The quantity of losses in the river can be measured with an aid of ________
a) Runoff coefficient
b) Hydrograph
c) River Coursing
d) River gauging
View Answer
Answer: d
Explanation: By measuring river discharge for number of years, it is possible to know the available and dependable supply. The river gauging helps in measuring discharge in the river and the quantity of losses can also be known.
37 - Question
The site for the river gauging station should not be liable to ____________
a) Silting
b) Coursing
c) Meandering
d) Runoff
View Answer
Answer: a
Explanation: River gauging station site should be selected in such a way that the site should be stable and there should not be any choice of scouring and silting. At the gauge site, the river section should be at right angles to the flow of the river.
38 - Question
Stage discharge relationship method is also known as ________ method.
a) Velocity Volume
b) Velocity Area
c) Distance Area
d) Displacement Momentum
View Answer
Answer: b
Explanation: Stage discharge relationship method is a direct method of computing a discharge in a stream by measuring velocity and area of flow. The place where such measurements are taken is known as velocity area station and the method is known as the velocity area method.
39 - Question
Velocity in a river flow can be calculated by using _________
a) By current meter
b) By emperical formulae
c) By infiltration method
d) By hydrograph
View Answer
Answer: a
Explanation: The velocity flow at any point in an open channel or in a river can be most accurately and conveniently determined by a mechanical device called current metre in this device the velocity of flow can be read from rating table.
40 - Question
Which of the following method is not used in measuring the velocity of a stream?
a) By floats
b) By rod float
c) By hydrograph
d) By colour
View Answer
Answer: c
Explanation: Hydrograph is a method of estimation of runoff. While the rest of the methods used in measuring the velocity of a stream/ river or canal. Hydrograph is a graph which shows the variations of discharge with respect to time.
41 - Question
The maximum flood discharge is also known as ___________
a) Peak flow
b) Maximum flow
c) Peak discharge
d) Peak flood
View Answer
Answer: a
Explanation: The maximum rate of discharge during a period of runoff, which is caused by a storm, is called a peak flow maximum flood discharge. Estimation of maximum flood discharge is a first step in planning for flood regulation.
42 - Question
Which of the following method is used to estimate maximum flood discharge?
a) By travelling screen
b) By current meter
c) By physical indication of past floods
d) By salt velocity
View Answer
Answer: c
Explanation: The results obtained by the physical indication of past floods methods are somewhat reliable. By oral enquiry in the villages situated on the banks of the river, the maximum water level attained in the past 35 years can be obtained. But this method is out-dated.
43 - Question
________formula is used only in southern India for calculating maximum flood discharge.
a) Dickens
b) Ryve’s
c) Lacey’s
d) Francis
View Answer
Answer: b
Explanation: Ryve’s (1884) formula is used only in Southern India.
Q = C(A)2/3.
The coefficient “C” depends on the maximum intensity of rainfall and other factors such as shape slopes exedra of the catchment.
44 - Question
A catchment area of 30.5 km2 is situated in Central India calculate the maximum discharge coming from the catchment area.
a) 253.08 cumecs
b) 341.06 cumecs
c) 457.88 cumecs
d) 485.66 cumecs
View Answer
Answer: a
Explanation: As the catchment area is situated in central India. Dicken’s formula is suitable and a maximum value of Dickens Coefficient is taken as 19.5
Q = CA3/4
Q = 19.5 × (30.5)3/4
Q = 253.08 cumecs.
45 - Question
If the catchment area is situated in north India, then what is the flood coefficient?
a) 10.45
b) 11.37
c) 12.6
d) 19.4
View Answer
Answer: b
Explanation: Dicken’s formula (1865)
Region Value of C
North India 11.37
Central India 11.77 – 19.28
Western India 22.04