GATE ME: Machine Design Champion Quiz 1 for ESE & GATE ME Exams

Question 1

For the given fluctuating fatigue load, the values of stress amplitude and stress ratio are respectively.

Question 2

A rotating shaft carrying a unidirectional transverse load is subjected to:

Question 3

Fatigue strength of a rod subjected to cyclic axial force is less than that of a rotating beam of the same dimensions subjected to steady lateral force. What is the reason?

Question 4

The failure occurs at a point in a member, when the maximum shear stress in a bi-axial stress system reaches the shear stress at elastic limit in simple tension test, this is according to

Question 5

A forged steel link with uniform diameter of 30 mm at the centre is subjected to an axial force that varies from 40 kN in compression to 160 kN in tension. The tensile (S_u), yield (S_y) and corrected endurance (S_e) strengths of the steel material are 600 MPa, 420 MPa and 240 MPa respectively. The factor of safety against fatigue endurance as per Soderberg’s criterion is

Question 6

The principal stresses at a point inside a solid object are σ₁ = 100 MPa, σ₂= 100 MPa and σ₃= 0 MPa. The yield strength of the material is 200 MPa. The factor of safety calculated using Tresca (maximum shear stress) theory is n_T and the factor of safety calculated using von Mises (maximum distortional energy) theory is n_V. Which one of the following relations is TRUE?

Question 7

The life of a ball bearing at a load of 10 kN is 8000 hours. Its life in hours, if the load is increased to 20 kN, keeping all other conditions the same, is

Question 8

The piston rod of diameter 20 mm and length 700 mm in a hydraulic cylinder is subjected to a compressive force of 10 kN due to the internal pressure. The end conditions for the rod may be assumed as guided at the piston end and hinged at the other end. The Young’s modulus is 200 GPa. The factor of safety for the piston rod is

Question 9

Match List-I (theory of Failure) with List-II (predicted Ratio of Shear Stress to Direct Stress at yield Condition for Steel Specimen) select the correct answer using the code given below the lists:
List-I
A). Maximum shear Stress theory
B). Maximum energy of distortion theory
C). Maximum principle stress theory
D). Maximum principle strain theory
List-II
1). 1.0
2). 0.77
3). 0.577
4). 0.50

Question 10

In designing a shaft for variable loads, the S.N. diagram can be drawn by (S_ut stands for ultimate tensile strength and S_e for the endurance limit)