## Machine Design Three different weights fall from a certain height under vacuum. They will take

Times inversely proportional to weight to reach earth
None of these
Times proportional to weight to reach earth
Same time to reach earth

## Machine Design For unequal width of butt straps, the thicknesses of butt straps are

0.75 t for both the straps on the inside and outside
0.75 t for wide strap on the inside and 0.625 t for narrow strap on the outside
0.75 t for narrow strap on the inside and 0.625 t for wide strap on the outside
0.625 t for both the straps on the inside and outside

## Machine Design In case of pressure vessels having open ends, the fluid pressure induces

Shear stress
Longitudinal stress
None of these
Circumferential stress

0.5
0.65
0.2
0.35

1 in 48
1 in 16
1 in 32
1 in 100

## Machine Design Which of the following statement is correct regarding power screws?

Both (A) and (B)
The efficiency of a self locking screw can not be more than 50%
If the friction angle is less than the helix angle of the screw, then the efficiency will be more than 50%
The efficiency of Acme (trapezoidal) thread is less than that of a square thread