Fundamentals of springs: A torsion spring stores energy primarily through twisting of its coil and is commonly a helical form. Decide whether the statement “A torsion spring is a type of helical spring” is correct.

Introduction / Context:
Springs store energy and release it to perform work. Torsion springs deliver torque when their coils twist; most commonly, they are manufactured as helical coils with legs that apply or resist rotation. We evaluate whether classifying a torsion spring as helical is correct.

Given Data / Assumptions:

• Helical forms include compression, extension, and torsion variants.
• Energy storage is through angular deflection about the coil axis.
• Other torsional devices exist (torsion bars, spiral springs) but differ in form.

Concept / Approach:
The geometry of a typical torsion spring is a helix. While the load mode is torsion (not axial compression/extension), the physical construction is still a helical coil. Hence, “torsion spring” is a load-mode subclass within the helical spring family.

Step-by-Step Solution:
1) Identify the coil form (helix) and legs for torque application.2) Note the governing relation: M = k_t * theta, where M is torque and theta is angular deflection.3) Recognize typical applications: clothespins, hinges, counterbalances.4) Conclude that the helical construction classifies it as a helical spring.

Verification / Alternative check:
Manufacturer catalogs list torsion springs alongside compression and extension springs under helical categories.

Why Other Options Are Wrong:
“Incorrect”: Conflicts with common catalogs and textbooks.“Only flat strips can be torsion”: Spiral springs exist, but do not negate helical torsion types.“Bending only”: Torsion springs primarily twist about the coil axis.

Common Pitfalls:
Confusing load mode (torsion) with coil form; assuming torsion implies flat spiral only.

Final Answer:
Correct