# Circuit Theory/TR

A terminal is a place where a wire comes out of an electrical component.

Terminal relations for the 2 wire devices studied so far (resistors,
capacitors and inductors), describe the voltage across the two terminals
and the current entering and leaving the terminals (which is always the
same).

The terminal relations for a resistor are $v = i * R$ (called ohms law)

The terminal relations for a capacitor are $i = C * dv/dt$

The terminal relations for an inductor are $v = L * di/dt$

A power supply doesn\'t have a terminal relationship or equation
relating current and voltage. Either the current is constant (current
supply) or voltage is constant (voltage supply). The power is varied
depending upon what the circuit asks for.

One of the best places to build up your intuition or build your own
animated circuit simulations is at
falstad

