Advertisements
Advertisements
Question
Explain why potential difference is always less than the e.m.f. of a cell?
Advertisements
Solution
When a cell is in closed circuit, i.e., when current is drawn from it, then the potential difference between its electrodes is called the terminal voltage. It is always less than the e.m.f. because when charge flows in a circuit, some energy is spent in the flow of charge through the electrolyte of the cell.
APPEARS IN
RELATED QUESTIONS
What do you understand by the term "potential difference"?
The p.d. across a lamp is 12 V. How many joules of electrical energy are changed into heat and light when: a current of 2 A flows through it for 10 s?
A current of 200 mA flows through a 4 kΩ resistor. What is the p.d. across the resistor?
100 joules of heat is produced per second in a 4 ohm resistor. What is the potential difference across the resistor?
The V-I graph for a series combination and for a parallel combination of two resistors is shown in Fig – 8.38. Which of the two, A or B, represents the parallel combination? Give a reason for your answer.
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 ______.
The differences between the electrostatic potential of the positive end the negative end of an electric cell is the ______ of the cell.
State whether the potential is a scalar or vector?
A 10 m long wire of a particular material is of resistance 5Ω What will be the resistance if the wire is stretched to double its length?
Conceptual question.
Does a solar cell always maintain the potential across its terminals constant? Discuss
