MDSP ELEMENTS SET 5

The bearing characteristic number depends on

• (a) Length and diameter of the bearing and the radial load
• (b) Length and diameter of the bearing, bearing load and speed of rotation
• (c) Length and diameter of the bearing, bearing load and viscosity of the lubricant
• (d) Length and diameter of the bearing, bearing load, speed of rotation and viscosity of the lubricant.

If the load on a ball bearing is reduced to one-third, then its life would increase by

• (a) 3 times
• (b) 9 times
• (c) 27 times
• (d) 81 times

A machine element offers resistance to failure when an extemal force acts on it. This resistance per unit area is called:

• (a) Induced Stress
• (b) Shear Stress
• (c) Engineering Stress
• (d) None of the above.

A tension member of diameter D is designed with a Factor of Safety of 4. If the load and diameter are doubled, the Factor of Safety would be:

• (a) Unchanged
• (b) Doubled
• (c) Reduced to half
• (d) None of the above.

The ratio of Endurance Limit to Ultimate Tensile Strength for Cast Iron at 10⁶ cycles is:

• (a) 0.1-0.2
• (b) 0.4-0.5
• (c) 0.9-0.95
• (d) None of the above

Based on yield, Factor of Safety may be arbitrarily selected in the range of:

• (a) 2 to 3
• (b) 3 to 5
• (c) 8 to 9
• (d) None of the above.

Stress concentration in a machine component results from:

• (a) Abrupt changes in the cross-section of the component.
• (b) Pressure at points/areas of the component at which the load is applied.
• (c) Point to point variation in the properties of the material of the component.
• (d) Any of the above.

Based on fracture the Factor of Safety may be selected equal to:

• (a) 5-7
• (b) 1-2
• (c) 9-10
• (d) None of the above.

Stress concentration factor for a machine component is dependent:

• (a) Only on the geometry of the component.
• (b) Only on the material of the component.
• (c) On geometry as well as material of the component.
• (d) On factors other that geometry and material of the component.

The difference between the upper limit and lower limit of a dimension is known as:

• (a) Basic size
• (b) Actual size
• (c) Tolerance
• (d) Nominal size.