electromotive force emf and voltage

Electromotive Force (EMF) and Voltage - No current flows in a copper wire by itself, just as water in a horizontal tube does not flow. If one end of the tube is connected to a tank with water such that there is a pressure difference between the two ends of th..

No current flows in a copper wire by itself, just as water in a horizontal tube does not flow. If one end of the tube is connected to a tank with water such that there is a pressure difference between the two ends of the horizontal tube, water flows out of the other end at a steady rat..

Cell Potential or EMF of a Cell - The difference between the electrode potentials of two half cells is known as electromotive force or cell potential or cell voltage..

The difference between the electrode potentials of two half cells is known as electromotive force or cell potential or cell voltage..

E.M.F. or Cell Potential of a Cell - The electrochemical cell consists of two half cells where one of the half-cell has a higher value of reduction potential as compared to the other. As a result of this potential difference, there is a flow of electrons from the electrode with a lower re..

Current through a given area of a conductor is the net charge passing per unit time through the area. To maintain a steady current, we must have a closed circuit in which an external agency moves electric charge from lower to higher potential energy. The work done per unit charge by the source..

As said earlier, in the metals some of the electrons are not so tightly bound to the atoms. They drift in all directions. The free electrons in a wire XY will not flow in a particular direction unless they are forced to do s..

In this type, the moving element is a very thin and flexible aluminum ribbon, upon which the sound waves act directly. It vibrates in a transverse magnetic field and generates an electromotive force on the ribbon. The ribbon impedance is so low that a small step-up transformer ..

Two identical cells of EMF 1.5 V each joined in parallel provide supply to an external circuit consisting of two resistors of 17 W each joined in parallel. A very high resistance voltmeter reads the terminal voltage of the cell to be 1.4 V. What is the internal resistance..

Six lead-acid type of secondary cells, each of emf 20 V and internal resistance 0.015 W , are joined in series to provide a supply to a resistance of 8.5 W . Determine (i) the current drawn from the supply and (ii) it's voltage..