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  What is a Transmission Line? Transmission line ek aisa system hota hai jo high-frequency signals ko ek jagah se dusri jagah carry karta hai. 👉 Jab conductor ki length signal wavelength ke comparable ho jaati hai, tab lumped circuit theory fail ho jaati hai aur transmission line theory apply hoti hai. Examples: Coaxial cable Open wire line Microstrip line Distributed Parameter Model of Transmission Line Transmission line ko distributed parameters ke form me represent kiya jaata hai: R → Resistance per unit length L → Inductance per unit length C → Capacitance per unit length G → Conductance per unit length 👉 Ye parameters poori length me continuously distributed hote hain. Types of Transmission Lines 1. Open Wire Transmission Line Do parallel conductors Low cost Noise interference zyada 2. Coaxial Cable Inner conductor + outer shield High noise immunity TV cable, RF communication me use Transmission Line Equa...

  What is a Uniform Plane Wave? Uniform Plane Wave ek aisi electromagnetic wave hoti hai jisme: Electric field (E) aur Magnetic field (H) uniform hoti hain Wave ek fixed direction me travel karti hai Field ka variation sirf propagation direction me hota hai 👉 Example: Radio waves Microwave communication Free space propagation Wave Equation Maxwell’s equations se wave equation derive hoti hai: ∇ 2 E = μ ϵ ∂ 2 E ∂ t 2 \nabla^2 E = \mu \epsilon \frac{\partial^2 E}{\partial t^2} ∇ 2 E = μ ϵ ∂ t 2 ∂ 2 E ​ ∇ 2 H = μ ϵ ∂ 2 H ∂ t 2 \nabla^2 H = \mu \epsilon \frac{\partial^2 H}{\partial t^2} ∇ 2 H = μ ϵ ∂ t 2 ∂ 2 H ​ 👉 Ye equation batati hai ki EM waves space aur time dono me propagate karti hain. Solution of Wave Equation 1. Dielectric Medium Conductivity ≈ 0 Energy loss negligible E = E 0 e − j β z E = E_0 e^{-j\beta z} E = E 0 ​ e − j β z 👉 Mostly free space & insulating materials me hota hai. 2. Conducting Medium Conductivity h...

  What are Time Varying Fields? Jab electric field (E) aur magnetic field (B) time ke sath change hoti hain, to unhe time varying fields kehte hain. 👉 Ye fields mainly yahan use hoti hain: AC circuits Transformers Electric motors & generators Antennas Wireless communication Equation of Continuity for Time Varying Fields Equation of continuity charge conservation law ko represent karti hai. Statement Electric charge neither be created nor destroyed, it can only flow. Mathematical Expression ∇ ⋅ J = − ∂ ρ ∂ t \nabla \cdot J = -\frac{\partial \rho}{\partial t} ∇ ⋅ J = − ∂ t ∂ ρ ​ Explanation Agar current kisi region se bahar ja raha hai To wahan charge density kam ho jaati hai 👉 Ye equation time-varying current ke liye valid hoti hai. Maxwell’s Equations – Introduction James Clerk Maxwell ne 4 equations di jinhone electric aur magnetic fields ko unify kiya. Inhi equations par modern electrical & communication systems based hai...