GATE ME Machine Design : National Champion Test for ESE & GATE ME Exams

Question 1

Who postulated the maximum distortion energy theory _________?

Question 2

What is the main advantage of hydro-dynamic bearing over roller bearing?

Question 3

If the load on a ball bearing is halved, its life

Question 4

In sliding contact bearings, a positive pressure can be built and a load supported by a fluid only by the use of a

Question 5

Hydrodynamic bearings are preferred over rolling element bearings in some applications in which_____.

Question 6

In hydrodynamic bearings

Question 7

A single parallel fillet weld of total length L and weld size h subjected to a tensile load P, will have what design stress?

Question 8

Two plates are joined together by means of single transverse and double parallel fillet welds as shown in the given figure. If the size of fillet is 5 mm and allowable shear load per mm is 300 N, what is the approximate length of each parallel fillet?

Question 9

What is the safe static tensile load for a M36x4 C bolt of mild steel having yield stress of 280MPa and a factor of safety 1.5?(Core diameter(d_c)= 0.84 times Nominal diameter(d))

Question 10

Consider the following statements associated with variable loading of bolts.
1). Smaller the stiffness constant, larger will be the external load carried by the bolts.
2). Greater the pretension, lesser will be the value of the alternating load carried by the bolts.
3). In variable loading, component will variable load is more dangerous than component with static load.
4). A high value of pretension is undesirable against fatigue failure.
Which of the statements are correct?

Question 11

In a band brake the ratio of tight side band tension to the tension on the slack side is 3. If the angle of overlap of band on the drum is 180 ° the coefficient of friction required between drum and the band is

Question 12

A block–brake shown below has a face width of 300 mm and a mean co–efficient of friction of 0.25. For an activating force of 400 N, the braking torque in Nm is
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Question 13

Which one of the following is not a friction clutch?

Question 14

A clutch has outer and inner diameters 100 mm and 40 mm respectively. Assuming a uniform pressure of 2 MPa and coefficient of friction of linear material 0.4, the torque carrying capacity of the clutch is

Question 15

A thin spherical pressure vessel of 200 mm diameter and 1 mm thickness is subjected to an internal pressure varying from 4 to 8 MPa. Assume that the yield, ultimate, and endurance strength of material are 600, 800 and 400 MPa respectively. The factor of safety as per Goodman’s relation is

Question 16

An axial residual compressive stress due to a manufacturing process is present on the outer surface of a rotating shaft subjected to bending. Under a given bending load, the fatigue life of the shaft in the presence of the residual compressive stress is

Question 17

In a structure subjected to fatigue loading, the minimum and maximum stresses developed in a cycle are 200 MPa and 400 MPa respectively. The value of stress amplitude (in MPa) is _________

Question 18

A spur gear has a module of 3 mm, number of teeth 16, a face width of 36 mm and a pressure angle of 20 °. It is transmitting a power of 3 kW at 20 rev/s. Taking a velocity factor of 1.5, and a form factor of 0.3, the stress in the gear tooth is about

Question 19

A bolt of major diameter 12 mm is required to clamp two steel plates. Cross sectional area of the threaded portion of the bolt is 84.3mm². The length of the threaded portion in grip is 30 mm, while the length of the unthreaded portion in grip is 8 mm. Young's modulus of material is 200 GPa. The effective stiffness (in MN/m) of the bolt in the clamped zone is ______

Question 20

A bolted joint has four bolts arranged as shown in figure. The cross sectional area of each bolt is 25 mm². A torque T = 200 N-m is acting on the joint. Neglecting friction due to clamping force, maximum shear stress in a bolt is_____ MPa.

Question 21

A multi-disc clutch employs 3 steel and 2 bronze discs having outer diameter of 300mm and inner diameter of 175mm. If the coefficient of friction is 0.25 and axial force on each pair of surfaces is 5kN, then the torque transmitted (assuming uniform wear) is

Question 22

For the three bolt system shown in the figure, the bolt material has shear yield strength of 200 MPa. For a factor of safety of 2, the minimum metric specification required for the bolt is

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Question 23

Large speed reductions (greater than 20) in one stage of a gear train are possible through

Question 24

A wire rope is designated as 6 × 19 standard hoisting. The numbers 6 × 9 represent

Question 25

A ball bearing operating at a load F has 8000 hours of life. The life of the bearing, in hours, when the load is doubled to 2F is