If an unsupported uniform cross sectional elastic bar is subjected to a longitudinal impact from a rigid bob moving with velocity v, then a compressive wave of intensity sc is propagated through the bar as follows______________________?

Related Mcqs:

1. In the case of an elastic bar fixed at upper end and loaded by a falling weight at lower end, the shock load produced can be decreased by_________________?

   A. decreasing the cross-section area of’ bar
   B. increasing the cross-section area of bar
   C. remain unaffected with cross-section area
   D. would depend upon other factors
   E. none of the above

2. If a load W is applied instantaneously on a bar; then the stress induced in bar will___________________?

   A. be independent of ratio of mass of load W to mass of bar (y)
   B. increase with increase in y
   C. decrease with decrease in y
   D. depend on other considerations
   E. none of the above

3. At low temperatures (say 75°C) the notched-bar impact value of steel____________________?

   A. increases markedly
   B. decreases markedly
   C. remains same
   D. depends on heat treatment carried out
   E. none of the above

4. Elastic nut is a locking device in which__________________?

   A. one small nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
   B. a slot is cut partly in middle of nut and then slot reduced by tightening a screw
   C. hard fiber or nylon cotter is recessed in the nut and becomes threaded as the nut is stewed on the bolt causing a tight grip
   D. through slots are made at top and a cotter-pin is passed through these and a hole in the bolt, and cotter pin splitted and bent in reverse direction at other end
   E. none of the above

5. The maximum stress due to stress concentration in a bar having circular transverse hole, as compared to its static stress without hole will be_________________?

   A. same in both cases
   B. 2 times more
   C. 3 times more
   D. 4 times more
   E. unpredictable

6. The property of a material which enables it to resist fracture due to high impact loads is known as__________________?

   A. elasticity
   B. endurance
   C. strength
   D. toughness
   E. resilience

7. The notch angle of the Izod impact test specimen is________________?

   A. 10°
   B. 20°
   C. 30°
   D. 45°
   E. 60°.

8. In testing a material for endurance strength, it is subjected to_______________________?

   A. static load
   B. dynamic load
   C. impact load
   D. static as well as dynamic load
   E. completely reversed load

9. The building up of worn and uridersized parts, subjected to repeated loads by electroplating is_____________________?

   A. best method
   B. extremely hazardous
   C. has no effect as regards fatigue strength
   D. cheapest method
   E. all of the above

10. When a close coiled helical spring is compressed, its wire is subjected to________________?

    A. tension
    B. shear
    C. compression
    D. all of the above
    E. none of the above