KSET 2025_Que. 03. Conductivty in metal

📘 Conductivity in Metals | Drift Velocity | Relaxation Time | Current Density | Complete Theory for Competitive Exams

In this lecture, we cover Conductivity in Metals from the perspective of competitive physics exams like CSIR-NET, GATE, JEST, MSc & PhD Entrance Exams.

This video explains the complete microscopic theory of electrical conduction using the Drude model, including:

🔹 Drift Velocity

𝑣
𝑑
=
𝑒
𝐸
𝜏
𝑚
v
d
​

=
m
eEτ
​
🔹 Relaxation Time (Mean Free Time)

𝜏
=
𝜆
𝑣
τ=
v
λ
​
🔹 Current Density

𝐽
=
𝑛
𝑒
𝑣
𝑑
=
𝜎
𝐸
J=nev
d
​

=σE

🔹 Electrical Conductivity

𝜎
=
𝑛
𝑒
2
𝜏
𝑚
σ=
m
ne
2
τ
​

📌 Topics Covered

✔ Motion of free electrons in metals
✔ Effect of electric field on electrons
✔ Derivation of drift velocity
✔ Physical meaning of relaxation time
✔ Relation between current density and electric field
✔ Microscopic form of Ohm’s Law
✔ Important derivations for exams
✔ Conceptual clarity + exam-oriented shortcuts

🎯 Who Should Watch?

✅ CSIR-NET Physics
✅ GATE Physics
✅ JEST
✅ MSc Entrance Exams
✅ University Semester Exams
✅ BSc/MSc Physics Students

🧠 Why This Video Is Important?

This topic forms the foundation of:

Solid State Physics

Condensed Matter Physics

Semiconductor Physics

Transport Phenomena

Many numerical and conceptual MCQs are directly asked from this area.

📢 Don’t Forget To

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📝 Comment your doubts

Видео KSET 2025_Que. 03. Conductivty in metal канала V K Lectures