Q2 of 5 Page 127

What is Kirchhoff’s second law?

Kirchhoff’s second law

Around any closed loop of a network, the algebraic sum of changes in potential must be zero. OR, the algebraic sum of EMFs in any loop of a circuit is equal to the sum of the product of currents and resistances in it.


Mathematically the loop rule may be expressed as




The sign convention for applying the rule:


1. We can take any direction (clockwise or anticlockwise) as the direction of traversal


2. The emf of the cell is taken as positive if the direction of traversal is from negative to the positive terminal (through the electrolyte)


More from this chapter

All 5 →
1

A potentiometer wire of length 1m has a resistance of 10 ohms. It is connected to a 6V battery in series with a resistance of 5 ohms. Determine the EMF of a primary cell 'e' which gives a balance point of 40 cm.

 3

Two students X and Y experiment potentiometer separately using the circuit diagram here. Keeping other things unchanged (i) X increases the value of resistance R (ii) Y decreases the value of resistance S in the setup. How will these changes affect the position of the null point in each case and why?

 4

A current of 1 ampere flows in series circuit contains an electric lamp and a conductor of 5 ohms when connected to a 10V battery. Calculate the resistance of the electric lamp. Now if a resistance of 10 ohms is connected in parallel with this series combination what change in current flowing through 5-ohm conductor and the potential difference across the lamp will take place? Give reason.

 5

State Ohm's law and mention its limitations.