Flat spiral springs A. Consist of uniform thin strips B. Are supported at outer end C. Are wound by applying a torque D. All the above

The correct answer is D. All of the above.

Flat spiral springs are made of uniform thin strips that are wound by applying a torque. The strips are supported at the outer end, and the spring is under tension when it is not compressed. When the spring is compressed, the strips are forced to bend, and this causes the spring to store energy. When the spring is released, the energy is released and the spring returns to its original shape.

Flat spiral springs are used in a variety of applications, including doorstops, suspension systems, and toys. They are also used in some medical devices, such as pacemakers.

Here is a more detailed explanation of each option:

• Option A: Flat spiral springs consist of uniform thin strips. This is true because the strips are made of a single piece of material, and they are all the same thickness. This makes the spring more consistent and reliable.
• Option B: Flat spiral springs are supported at the outer end. This is true because the strips are attached to a frame or other structure at the outer end. This prevents the strips from buckling or collapsing when the spring is compressed.
• Option C: Flat spiral springs are wound by applying a torque. This is true because the strips are wound around a central axis. This creates the tension that holds the spring in its shape.

I hope this explanation is helpful. Please let me know if you have any other questions.