The document discusses Kirchhoff's laws, which include Kirchhoff's Current Law (KCL) stating that the total current entering a junction equals the current leaving it, and Kirchhoff's Voltage Law (KVL) indicating that the sum of voltages in a closed path equals zero. It also differentiates between active and passive components, as well as unilateral and bilateral elements, and outlines linear versus nonlinear elements. Additionally, the document describes mesh analysis as a technique to determine unknown currents in circuits using KVL.

1. BASIC ELECTRICAL
ENGINEERING
TOPIC- KCL & KVL

2. Kirchhoff’s Law
• German Physicist Kirchhoff proposed two
important laws which can be applied to solve
problems electric circuit.
• Kirchhoff's current law (KCL)
• Kirchhoff's voltage law (KVL)
• Kirchhoff's Current Law (KCL)
• Kirchhoff’s current law states that the
algebraic sum of all the current meeting at a
point is equal to zero.

3. Contd...
• The total current entering a junction or a node
is equal to the current leaving the node.
• i.e sum of incoming current=sum of outgoing
current
• 0

I

4. Kirchhoff's Voltage Law (KVL)
• Kirchhoff’s Voltage Law states that the
algebraic sum of the voltages (or voltage
drops) in any closed path is equal to zero.
• In other words, in a closed circuit, the
algebraic sum of all the EMFs and the
algebraic sum of all the voltage drops (product
of current (I) and resistance (R) is zero.
0



 V
E

5. Contd...

6. Contd..

7. ACTIVE & PASSIVE ELEMENT
• ACTIVE ELEMENTS
• An active element is an electrical component which
supplies energy to a circuit. Active elements have the
ability to electrically control electron flow (i.e. the flow
of charge).
• Common examples of active components include:
Voltage sources, current sources, transistors, generators
• PASSIVE ELEMENTS
• A passive component is an electrical component which
can only receive energy, which it can either dissipate,
absorb or store it in an electric field or a magnetic field.
• Ex- Resistor, inductor and capacitor

8. Unilateral & Bilateral Elements
• The elements in which Conduction of current in one direction
is termed as unilateral elements.
• Example- Diode & Transistor

9. Contd...
• Bilateral Elements
• Bilateral elements are defined as the elements
through which Conduction of current in both
directions.
• Example- Resistor, Inductor, capacitor

10. Linear & Nonlinear Elements
• The circuit elements which are always constant
irrespective of change in time, voltage, temperature
etc is known as Linear Elements.
• Ex- Resistor, Inductor & Capacitor
• A nonlinear circuit is an electric circuit whose
parameters are varied with respect to Current and
Voltage.
• In other words, an electric circuit in which circuit
parameters is not constant, is called Non Linear
Circuit.
• Example- Diode, Transistor, Transformer

11. NODE, JUNCTION,BRANCH, LOOP, MESH

12. Sign Convention for KVL

13. Network Vs Circuit
• Network/Circuit
• An electrical network is an interconnection of
active and passive elements such as resistance,
inductance, capacitance and sources.
• An electrical circuit is a network that has a
closed loop, giving a return path for the current.
• A network is a connection of two or more
components and may not necessarily be a
circuit.

14. Mesh Analysis
• Mesh Current Analysis is a technique used to find the
currents circulating around a loop or mesh.
• Mesh analysis applies the Kirchhoff’s Voltage Law
(KVL) to determine the unknown currents in a given
circuit. Mesh analysis is also called as mesh-current
method or loop analysis.

15. PROBLEMS

16. Contd...