There is a potential difference (voltage) between two points and a path for electrons to travel from an area of low potential (negative) to an area of high potential (positive). Note the direction of "current flow" is opposite the direction of electron flow. In other words current flows from positive to negative. In a circuit involving only a resistor, the current flowing in the circuit is given by I=V/R where I = current, V= voltage, and R=resistance.
To avoid that the plates touch each other.
The better the dielectric, the closer the plates can be, thus making the electrostatic field on the opposite plates more intense, which allows for more electrons displaced via the charging circuit to the positive plate and more incomplete atoms (positive charges) left on the negative plate.
Remember: Being the dielectric an isolator, there is NEVER current through the capacitor.
Inductive circuit..remember ELI the ICE man, E=voltage, I=current, L=inductance, C=capacitance
An inductor looks like a piece of wire to DC. It will thus look like a resistor, and inductor properties do not apply.
Mostly because of their cost but also because silicon transistor have faster switching properties and are far more resistant to damage by heat. Silicon transistor also have a much wider operating band.