ANSWER is 1 volt.One volt is the POTENTIAL difference between two points in a current-carrying CONDUCTOR when 1 joule of work is done to move a charge of 1 coulomb from one point to the other.The unit of Potential difference is Volt.The potential difference is measured by an instrument called a voltmeter. The first digital voltmeter was invented and produced by Andrew Kay of Non-Linear Systems (and later founder of Kaypro) in 1954.Ampere is the SI unit of current.Ohm is the unit of Resistance.Newton is the unit of Force.Resistance is a measure of the opposition to current FLOW in an electrical circuit.A force is any interaction that, when unopposed, will change the motion of an object. One Ampere represents a flow of one coulomb of electrical charge per second.