the potenial difference of a dry cell 1.5v.what foes it mean
Answers
By definition, 1 V is a potential energy difference of one joule PER COULOMB of charge between two points. That answers your question. 1.5V means that there is a potential energy difference of 1.5 joules per coulomb between the points where that potential difference is measured.
EMF or Electro Motive Force is a misnomer of sorts and a legacy of the days when electricity was poorly understood. It is not really a force but is used to refer to the potential difference between to points, say between the terminals of a battery, and, therefore, is a scalar quantity. It is defined as the work done per charge dW/dq.
To further answer your question, we could take 1.5V emf to mean an energy difference of 1.5 joules/coulomb between the positive and negative terminals of the battey. That is to say, you could consider the battery to be a charge pump that is capable of doing a work of 1.5 joules per coulomb of charge if sent from one terminal to the other.
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