Strength of Material (General Engineering) (SSC JE)

Total Questions: 50

41. Which of the following is a deficiency frame? [APPSC AE PRE.-15.05.2022 ]

Correct Answer: (b)
Solution:


42. The method of joints is preferred in the analysis of plane frames if forces are required to be determined in: [APPSC AE PRE.-15.05.2022 ]

Correct Answer: (d) In all the members
Solution:

Method of joint is used to find the unknown forces at the joints in a truss problem.
Method of joint–At each joint the forces in the members meeting and the loads acting constitute a system of concurrent forces.
Hence, two independent equations of equilibrium can be formed at each joint (Horizontal and vertical equilibrium).
• A joint is selected where there are only two unknown force. First reactions at the support are calculated by considering the equilibrium of the entire truss frame.

43. The force in member AD of the truss shown in the following figure is (take D and E as the mid-point of AC and BC, respectively): [APPSC AE PRE.-15.05.2022 ]

Correct Answer: (d) –80 kN
Solution:



44. The variation of shear stress in a circular shaft, subjected to torsion, with radial distance is: [APPSC AE PRE.-15.05.2022 ]

Correct Answer: (a) Linear
Solution:


i.e. angle of twist remains constant after twisting
(c) Shaft is loaded by twisting couples in planes that are perpendicular to the axis of shaft.
(d) Stress do not exceed proportional limit.
Note–(i) Strain variation is linear over cross-section
(ii) Shear stress variation is also linear over crosssection (τ ∝ r)

45. The neutral axis of cross-section of a beam is that axis at which the bending stress is [BPSC AE (GEN. ENGG.)-13.03.2022 ]

Correct Answer: (a) zero
Solution:

Stress distribution on a cross-section of a beam– •
A beam deforms under the influence of a positive bending moment. The segment assumes the characteristic "bent" shape as the upper fibers are shorted and the lower fiber are elongated.

• The neutral axis, coincident with the centroidal axis of the cross-section of the beam, bends, but it is not strained. Therefore, at the neutral axis the stress due to bending is zero.
• In figure, bending stress distribution in symmetrical section.

46. Factor of safety is [BPSC AE (GEN. ENGG.)-13.03.2022 ]

Correct Answer: (c) ultimate stress/permissible stress
Solution:

Factor of safety is the ratio of ultimate stress to permissible stress.
Factor of safety =  Ultimate stress/Permissible stress

47. The notch angle of the izod impact test specimen is - [RSMSSB JE (E&M) Degree - 26/12/2020]

Correct Answer: (d) 45⁰
Solution:Types of impact test–
Izod impact test → specimen positioned like cantilever.
Charpy impact test → specimen positioned like simply supported beam.
• In Izod impact test a V-shaped notch is created on the surface of specimen in order to initiate the cracking.
The notch angle of the specimen is 45º.

48. 0.2 percent proof stress means [BPSC AE (GEN. ENGG.) 15.09.2018 ]

Correct Answer: (c) stress at which if unloading is made, there will be 0.2 percent permanent set
Solution:

0.2% proof stress is defined as the stress at which if loading is applied, there will be 0.2% of permanent deformation takes place. It is used to find out yield strength of brittle material in which yield point is not clearly defined.

49. In case of steel, the strain at yield point is [BPSC AE (GEN. ENGG.) 15.09.2018 ]

Correct Answer: (b) 0.125%
Solution:

The strain at yield point in steel is about to 0.125%.

50. In case of brittle materials, the ratio of ultimate compressive stress to ultimate tensile stress is [BPSC AE (GEN. ENGG.) 15.09.2018 ]

Correct Answer: (b) more than 1
Solution:

In case of brittle or ductile materials, the compressive strength is more than the tensile strength of individual materials.
Hence the ratio of ultimate compressive stress to ultimate tensile stress is always more than 1.