Radius vs Energy in Magnetic Field — JEE Concept in 59 Sec 🔥
❓ Question A particle of charge q q q , mass m m m and kinetic energy E E E enters a uniform magnetic field perpendicular to its velocity and undergoes a circular arc of radius r r r . Which of the following curves correctly represents the variation of r r r with E E E ? 🖼️ Question Image ✍️ Short Explanation This is a pure relation-based magnetism question . No numbers. No tricks. 👉 Sirf radius–energy dependence samajhni hai. 🔹 Step 1 — Magnetic force causes circular motion For a charged particle moving perpendicular to magnetic field B B B : q v B = m v 2 r So radius of circular path: r = m v q B 📌 Radius speed v v v par depend karta hai. 🔹 Step 2 — Connect speed with kinetic energy Kinetic energy: E = 1 2 m v 2 So: v = 2 E m v=\sqrt{\frac{2E}{m}} Substitute in radius expression: r = m q B 2 E m r=\frac{m}{qB}\sqrt{\frac{2E}{m}} Hence: r ∝ E \boxed{r\propto \sqrt{E}} 🔹 Step 3 — Nature of r vs E graph (MOST IMPORTANT 🔥)** From: r ∝ E r\pro...