Advertisements
Advertisements
प्रश्न
Point out two differences between e.m.f. and potential difference as applied to electric circuits.
Advertisements
उत्तर
Electromotive force or e.m.f. of a cell is potential difference between its two electrodes when it is in open circuit, i.e., not sending current in the external circuit; while potential difference is the difference in potential between the terminals when the cell is in closed circuit or it is sending current in the given circuits, e.m.f. is always greater than potential difference or terminal voltage of a cell on account of energy being spent in driving charge through the circuit.
APPEARS IN
संबंधित प्रश्न
By what other name is the unit joule/coulomb called?
Name the law which relates the current in a conductor to the potential difference across its ends.
The following table shows current in Amperes and potential difference in Volts.
What will be the nature of the graph between the current and potential difference? (Do not draw a graph.)
The following table shows current in Amperes and potential difference in Volts.
Which law will the graph prove? Explain the law.
Write proper word from the following group of words in the blank.
(magnetism, 4.5V, 3.0V, gravitational attraction, potential difference, potential, higher, lower, 0V)
Water in the waterfall flows from a higher level to the lower level because of ______.
A V-I graph for a nichrome wire is given below. What do you infer from this graph? Draw a labelled circuit diagram to obtain such a graph.
Explain why potential difference is always less than the e.m.f. of a cell?
A current of 100 mA. flows through a wire. The charge on an electron is 1.6 × 10-19 C. Find the number of electrons passing per second through the cross-section of the conductor.
