1. What is Cutoff Frequency?

The cutoff frequency (f_c) is the frequency at which the output signal of a filter is reduced to half its power (-3dB point). For an RC circuit, it marks the transition between the passband and stopband.

2. How Does the Calculator Work?

The calculator uses the cutoff frequency formula:

Where:

• \( f_c \) — Cutoff frequency in Hertz (Hz)
• \( R \) — Resistance in Ohms (Ω)
• \( C \) — Capacitance in Farads (F)
• \( \pi \) — Mathematical constant (~3.14159)

Explanation: The formula shows the inverse relationship between cutoff frequency and the RC time constant.

3. Importance of Cutoff Frequency

Details: Cutoff frequency is crucial for designing filters, determining bandwidth, and analyzing circuit behavior in audio systems, signal processing, and communications.

4. Using the Calculator

Tips: Enter resistance in ohms and capacitance in farads. For practical values, remember that 1μF = 0.000001F. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What happens at the cutoff frequency?
A: The output voltage drops to 70.7% (1/√2) of the input voltage, which corresponds to -3dB in power.

Q2: How does changing R or C affect the cutoff frequency?
A: Increasing either R or C lowers the cutoff frequency, while decreasing them raises it.

Q3: What's the difference between low-pass and high-pass cutoff?
A: For low-pass, frequencies below f_c pass through. For high-pass, frequencies above f_c pass through.

Q4: Can I use this for RL circuits?
A: No, RL circuits use a different formula: f_c = R/(2πL).

Q5: Why is 3dB significant?
A: It represents the half-power point, where the signal's power is reduced by 50%.