This set of Strength of Materials Multiple Choice Questions on “Shear Stress and Twisting Moment”.
1. 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
Answer: b
Clarification: 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.
2. The shear stress is ____________ at the axis of the shaft.
a) Minimum
b) Maximum
c) Zero
d) Uniform
Answer: c
Clarification: 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.
3. The shear stress at the outer surface of hollow circular section is _________
a) Zero
b) Maximum
c) Minimum
d) Can’t determined
Answer: b
Clarification: 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.
4. 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
Answer: c
Clarification: 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.
5. The process of measurement of discharge and water level of a river is called _________
a) Meandering
b) River coursing
c) River gauging
d) Scouring
Answer: c
Clarification: 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.
6. 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
Answer: d
Clarification: 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.
7. The site for the river gauging station should not be liable to ____________
a) Silting
b) Coursing
c) Meandering
d) Runoff
Answer: a
Clarification: 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.
8. Stage discharge relationship method is also known as ________ method.
a) Velocity Volume
b) Velocity Area
c) Distance Area
d) Displacement Momentum
Answer: b
Clarification: 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.
9. 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
Answer: a
Clarification: 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.
10. 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
Answer: c
Clarification: 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.
11. The maximum flood discharge is also known as ___________
a) Peak flow
b) Maximum flow
c) Peak discharge
d) Peak flood
Answer: a
Clarification: 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.
12. 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
Answer: c
Clarification: 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.
13. ________formula is used only in southern India for calculating maximum flood discharge.
a) Dickens
b) Ryve’s
c) Lacey’s
d) Francis
Answer: b
Clarification: 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.
14. 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
Answer: a
Clarification: 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.
15. 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
Answer: b
Clarification: Dicken’s formula (1865)
| Region | Value of C |
| North India | 11.37 |
| Central India | 11.77 – 19.28 |
| Western India | 22.04 |