Ohms Law

The current produced in a circuit by a DC voltage is directly proportional to the DC voltage.  The constant of proportionality is resistance, R which is a property of matter and resistor demensions. 

V = IR

Ohms Low Demonstration
for I =V/R

Matter and Electricity

Electricity is a physical phenomena involving positive and negative charge. When these charges are in motion they may produce heat, light and magnetism.  When charges are not in motion, static electricity can  manifests itself as a force such as clothes clinging to each other when they are removed from a dryer. 

A simple stationary system of a single positive ion and a single negative ion (or electron) separated by large distance with respect to their size ( a meter for example) will have a E field associated with them. Along the axis connecting the two ions the E vector points directly from the positive ion towards the negative ion.  At this theoretical point in time there is no H field. The E field will cause the charge particles to move towards each other.  This relative motion of positive and negative charge is the simplest example of current.  Associated with this tiny current a magnetic or H field will exist. The motion of the positive charge will be in the direction of the E field and the negative charge will move in the opposite direction of the E field. Current by definition flows in the direction of the E field.  It follows that positive charge moves in the direction of current and negative charge moves opposite to the current.