JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech II Year NETWORK THEORY Previous Question Paper (August/September - 2022 - R16)

Faraday's law of electromagnetic induction states that a change in the magnetic flux linked with a circuit induces an electromotive force (emf) in that circuit. The magnitude of the induced emf is directly proportional to the rate of change of the magnetic flux linkage.

In this expression, e is the induced emf, N is the number of turns in the coil, and dΦ/dt is the time rate of change of magnetic flux. The negative sign, known as Lenz's Law, indicates that the direction of the induced current is such that it opposes the change in magnetic flux that produced it, ensuring conservation of energy. The law can be demonstrated by moving a magnet relative to a stationary coil or by varying the current in a primary coil to change the flux through a secondary coil.

Duality is a property where two networks are described by the same set of mathematical equations, where the roles of voltage and current are interchanged. A dual circuit is one where the meshes of the original circuit become the nodes of the dual circuit.

The procedure to draw a dual circuit is as follows:

1. Place a node inside each mesh of the original network and one additional node outside the network (the reference node).
2. Draw lines connecting these nodes, passing through each branch of the original network.
3. Replace each element in the original branch with its dual element: a resistor becomes a conductance, an inductor becomes a capacitor, a voltage source becomes a current source, and series connections become parallel connections.
4. Ensure the polarity of the sources and the orientation of the branches follow the established convention to maintain the same mesh/node equations.