Capacitance Converter

import math

# Capacitance unit converter
CAPACITANCE_TO_FARAD = {
    "F":  1,
    "mF": 1e-3,
    "uF": 1e-6,   # µF
    "nF": 1e-9,
    "pF": 1e-12,
}

def convert_capacitance(value: float, from_unit: str, to_unit: str) -> float:
    """Convert between capacitance units via farad (F)."""
    value_in_farad = value * CAPACITANCE_TO_FARAD[from_unit]
    return value_in_farad / CAPACITANCE_TO_FARAD[to_unit]

def capacitive_reactance(capacitance_f: float, frequency_hz: float) -> float:
    """XC = 1 / (2π × f × C) in ohms."""
    if frequency_hz == 0:
        return float("inf")
    return 1 / (2 * math.pi * frequency_hz * capacitance_f)

# Examples
print(convert_capacitance(100, "nF", "uF"))      # 0.1 µF
print(convert_capacitance(0.01, "uF", "pF"))     # 10000 pF

# Reactance of 10µF at 1kHz
xc = capacitive_reactance(10e-6, 1000)
print(f"XC at 1 kHz: {xc:.2f} Ω")  # 15.92 Ω

# Charge stored: Q = C × V
c_farads = 100e-6  # 100 µF
voltage = 12       # volts
charge_coulombs = c_farads * voltage
print(f"Charge: {charge_coulombs * 1000:.2f} mC")  # 1.20 mC