 Solution

In the classical single-carrier model,for a two-dimensional sheet. The curve is a straight line through the origin, with its sign determined by the carrier charge and the voltage convention. The sheet Hall coefficient has units ${\mathrm{m}}^2/C$, consistent with the numerical slope used later.

The classical transverse response is not quantized. With carrier density and scattering parameters fixed, reversing $B$ reverses the transverse signal. Several carrier populations can produce a nonlinear classical curve, so straight-line behaviour here uses the stated single-population approximation rather than being a property of every conductor.