Lecture 4 : Physical Interpretation of Voltage & Current Solution
Current Travelling Waves
The first term of the current solution represents a current travelling wave in direction (left to right), and gives the amplitude of the wave at . We call this wave, the ' Forward Current Travelling Wave '
Similarly, the second term in the current solution gives a travelling wave but travelling in
negative ' x ' direction (right to left) as shown in Figure. gives the amplitude of the at . This wave we
call the
'Backward Current Travelling Wave' .
Important Conclusion
The Voltage and the Current exist in the form of waves on a transmission line.
In general, we can say that in a circuit, any time varying voltage and/or current always exist in the form of waves,
although the wave nature may not be evoked at low frequencies where the transit time effects are negligible.
represents a current travelling wave in 
direction (left to right), and 
gives the amplitude of the wave at 
. We call this wave, the 
gives a travelling wave but travelling in
negative ' x ' direction (right to left) as shown in Figure. 
gives the amplitude of the at 
