1. What is the Radius of Inner Circle of Annulus given Outer Circle Radius and Perimeter Formula?

The formula calculates the inner radius of an annulus when the outer radius and perimeter are known. An annulus is the region between two concentric circles, and this formula helps determine the size of the inner circle based on the given parameters.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( r_{Inner} \) — Inner Circle Radius of Annulus (m)
• \( P \) — Perimeter of Annulus (m)
• \( r_{Outer} \) — Outer Circle Radius of Annulus (m)
• \( \pi \) — Archimedes' constant (approximately 3.14159)

Explanation: The formula derives from the relationship between the perimeter of an annulus and the radii of its inner and outer circles.

3. Importance of Inner Circle Radius Calculation

Details: Calculating the inner radius is essential in various engineering and design applications, particularly in mechanical and civil engineering where annular shapes are common.

4. Using the Calculator

Tips: Enter the perimeter of the annulus and the outer circle radius in meters. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is an annulus?
A: An annulus is a ring-shaped object, the region between two concentric circles.

Q2: Can the inner radius be negative?
A: No, the inner radius must be a positive value. If the calculation results in a negative number, check your input values.

Q3: What units should I use?
A: The calculator uses meters, but you can use any consistent unit of length as long as both inputs are in the same unit.

Q4: How accurate is the calculation?
A: The calculation uses the mathematical constant π with high precision, providing accurate results based on your input values.

Q5: Can I use this for non-circular annuli?
A: No, this formula specifically applies to circular annuli formed by two concentric circles.