Strength of Materials  GATE practice papers  Mechanical
Here, you can read Strength of Materials multiple choice questions and answers with explanation.
1) Calculate the normal stress acting on the plane of maximum shear stress, considering the following state of stress shown in the figure. (Marks: 02)
 Published on 19 Oct 15
a. 30 MPa compression
b. 30 MPa tension
c. 15 MPa compression
d. 15 MPa tension
Answer
Explanation

ANSWER: 15 MPa compression
Explanation: Normal stress acting on the plane of maximum shear stress will be, (Taking compression as positive)
σ_{n} = (σ_{x}± σ_{y}) / 2 =(50 – 20) / 2 = +15
that is 15 MPa compression.


2) A spring of radius 1 cm obeys Hooke's law. A mass of 2 kg is attached to the spring. Calculate the extension of the spring. The spring constant k is 110 N/m  Published on 19 Oct 15
a. 17.81 m
b. 0.1781 cm
c. 0.1781 m
d. 0.1781 mm
Answer
Explanation

ANSWER: 0.1781 m
Explanation: According to the Hooke's law force applied to extend or compress a spring is directly proportional to change in length of the spring. Therefore F = – kX where k is spring constant. By using this formula and taking force applied F = mg = 2 × 9.8 =19.6 N and k = 110 N/m we can fine X.


3) Poisson's ratio is the ratio of ______(Marks: 01)  Published on 19 Oct 15
a. longitudinal strain to lateral strain
b. lateral strain to longitudinal strain
c. longitudinal stress to lateral strain
d. lateral stress to longitudinal strain
Answer
Explanation

ANSWER: lateral strain to longitudinal strain
Explanation: The ratio of lateral strain to longitudinal strain has a constant value and it is called as Poisson's ratio. Poisson's ratio is denoted by v


4) What is stress? (Marks: 01)  Published on 19 Oct 15
a. internal resistance offered by a body against deformation
b. external resistance offered by a body against deformation
c. internal force offered by a body against deformation
d. external force offered by a body against deformation
Answer
Explanation

ANSWER: internal resistance offered by a body against deformation
Explanation: Stress is an internal resistance offered by a body or a material against deformation. It is a resisting force per unit area.

