A power screw is only used to convert rotary motion into linear motion and not for transmitting power.
Explanation: Power screw converts the motion from rotary to linear and is used for power transmission.
Depending upon the holding arrangement, power screws operate in how many different arrangements.
Explanation: There are two types of arrangements. In one screw rotates while nut remains stationary and vice versa.
V threads are highly recommended for fastening as well as power transmission purpose.
Explanation: In fastening, high frictional force is required and hence V threads are used whereas in power transmission, reduction in frictional forces is required.
A power screw has no problem of wear as there is very less amount of friction associated.
Explanation: Wear is a serious problem in power screws as there is high friction in threads.
Trapezoidal threads are better than square threads as there is radial pressure or side thrust on the nut.
Explanation: Trapezoidal and not square threads suffer from the problem of bursting.
Trapezoidal threads screws have less load carrying capacity as compared to square thread screws.
Explanation: Square threads have less thickness at the core diameter and hence lower load carrying capacity.
Which of the following are true for buttress threads?
Explanation: As force is applied only in one direction in a vice so buttress threads are used.
Tr 40 x 14(P 7), here 14 indicates
Explanation: Tr=Trapezoidal threads,14=Lead(mm),7=Pitch(mm).
If nominal diameter of screw thread=50mm and pitch=10mm then the mean diameter of the screw thread will be?
Explanation: Diameter(mean)=Diameter(nominal) – 0.5P .
If the load itself begin to the screw and descend down, unless a restraining torque is applied then the condition is termed as
Explanation: Overhaulting is the condition when load itsel begin to turn the screw.