Consider a capacitor with a varying voltage applied to it. As the voltage changes over time, the electrical field $\vec{E}$ inside the plates does too.
Assumption We assume that the direction of $\vec{E}$ is the same inside the capacitor, hence ignoring border effects.
According to Ampere-Maxwell (Maxwell's 4th equation):
$$ \nabla \times \vec{B} = \mu_0 \vec{j} + \frac{1}{c^2}\frac{\partial \vec{E}}{\partial t} $$
A magnetic field $\vec{B}$ is generated. How do I find out the direction of the magnetic field? Basically, how do I find out the field lines of $\vec{B}$ inside the capacitor?
Ultimately, how can we find the equations of the field lines?