import math


def dcr_of_annulus(
    thickness: float, inner_radius: float, outer_radius: float, rho: float = 1.68e-8
):
    """Calculate the sheet resistance of an annulus
    """

    assert (
        outer_radius > inner_radius
    ), f"Outer radius must be greater than inner radius"

    resistance = (2e3 * math.pi * rho) / (
        thickness * (math.log(outer_radius / inner_radius))
    )

    return resistance