Doubtify – JEE Ki Taiyaari, Simple Bhasha Mein

  ❓ Concept 🎬 EM Waves: Dimension of ε 0 d Φ E d t \varepsilon_0 \dfrac{d\Phi_E}{dt} ​ ​ in 59 Sec Electric flux ka time-rate diya ho… aur uske saath ε 0 \varepsilon_0 ​ multiply ho raha ho… 👉 Toh sawal sirf maths ka nahi hai — physics ka meaning samajhne ka hai ⚡🤔 🖼️ Concept Image ✍️ Short Explanation JEE is concept ko isliye pyaar karta hai kyunki yahin se Maxwell equations aur EM waves ka foundation banta hai. Agar tumhe yeh samajh aa gaya, 👉 dimensions + theory dono clear . 🔹 Step 1 — Electric Flux Meaning (FOUNDATION 💯)** Electric flux: Φ E = ∮ E ⃗ ⋅ d A ⃗ So dimensionally: Electric field E E Area A A [ Φ E ] = [ E ] × [ Area ] 📌 Matlab: Flux measures how much electric field passes through a surface . 🔹 Step 2 — Time Rate of Electric Flux d Φ E d t​ ​ Iska matlab: Electric field time ke saath change ho raha hai Ya surface ke through field flow vary kar raha hai 📌 Yeh quantity batati hai: Electric field kitni tezi se ...

❓ Question If ε 0 \varepsilon_0 ​ denotes the permittivity of free space and ϕ E \phi_E  is the electric flux through the area bounded by a closed surface, then the dimensions of ε 0   d ϕ E d t are the same as that of what physical quantity? 🖼️ Question Image ✍️ Short Solution This is a pure dimensional-analysis + concept question from Electrostatics + Maxwell’s equations . No numbers, no calculus — just definitions and dimensions . 🔹 Step 1 — Meaning of electric flux Electric flux through a closed surface is: ϕ E = ∮ E ⃗ ⋅ d A ⃗ So dimensionally: [ ϕ E ] = [ E ]   [ A ] 🔹 Step 2 — Dimensions of electric field Electric field: E = F q Where: Force F F  has dimensions [ M L T − 2 ] [MLT^{-2}] Charge q q q has dimensions [ I T ] [IT] So: [ E ] = M L T − 2 I T = M L T − 3 I − 1 🔹 Step 3 — Dimensions of electric flux Area: [ A ] = L 2 Hence: [ ϕ E ] = ( M L T − 3 I − 1 ) ( L 2 ) = M L 3 T − 3 I − 1 🔹 Step 4 — Take time derivative of flux ...