Question

Consider the following statements for a shuttle loom having linear (straight line) displacement profile for the picker:
P. The maximum actual acceleration of shuttle depends on loom speed and alacrity of picking system
Q. The maximum actual velocity of shuttle depends on loom speed
R. The maximum actual acceleration and maximum actual velocity of shuttle occur at the same time
S. Nominal displacement of shuttle is inversely proportional to the angular movement of crank shaft
The combination of TRUE statements is:

• A. P and Q
• B. Q and R
• C. R and S
• D. P and R

Hint:

Acceleration peaks early in motion; velocity peaks later. They cannot occur simultaneously in a shuttle loom.

Answer 1

The Correct Option is A

To analyse the truth of statements P, Q, R, and S, we must clearly understand the kinematics of shuttle motion in a traditional shuttle loom. The shuttle is propelled by a picker through the picking stick, following a nearly straight-line displacement profile. The acceleration and velocity of this shuttle depend heavily on loom speed and the picking mechanism’s response. Statement P is true because the shuttle’s acceleration increases with loom RPM. As the loom speed rises, the pick must be completed in a shorter time, increasing the rate of change of velocity. Furthermore, the alacrity (responsiveness) of the picking system influences how fast force is transmitted to the shuttle. If the picking stick is stiff and responsive, the shuttle reaches higher acceleration more rapidly; if sluggish, acceleration is lower. Hence, P is correct. Statement Q is also true. Maximum velocity of the shuttle is directly governed by loom speed because increasing loom RPM reduces the time available for shuttle flight. Since the displacement remains constant, reducing flight time necessarily increases velocity. Thus, Q is correct. Statement R is false because acceleration and velocity peaks never coincide in linear motion. Maximum acceleration occurs near the start of motion where force is highest, while maximum velocity occurs later when net acceleration drops to zero. Therefore, R is incorrect. Statement S is false because nominal shuttle displacement is fixed by loom geometry and is not inversely proportional to crankshaft rotation. It is determined by shuttle race length, not crank angle. Thus the correct pair is P and Q.