Doubtify – JEE Ki Taiyaari, Simple Bhasha Mein

  ❓ Question Two charges q 1 q_1 ​ and q 2 q_2 ​ are separated by a distance of 30 cm . A third charge q 3 q_3 ​ , initially at C (as shown), is moved along a circular path of radius 40 cm from C to D . If the change in potential energy of q 3 q_3 ​ due to this movement is q 3 K 4 π ε 0 , \frac{q_3 K}{4\pi\varepsilon_0}, find the value of K K . 🖼️ Question Image ✍️ Short Solution This is a pure potential-energy difference problem . 👉 Path does NOT matter — only initial and final positions matter. We compare the electric potential at C and D due to fixed charges q 1 , q 2 q_1, q_2 . 🔹 Step 1 — Understand the Geometry (MOST IMPORTANT 💯)** From the figure: q 1 q_1 ​ at point A q 2 q_2 ​ at point B A B = 30  cm AB = 30\text{ cm} A C = 40  cm AC = 40\text{ cm}  (vertical) Arc CD is a quarter circle of radius 40 cm , centred at A So: A D = 40  cm AD = 40\text{ cm} B D = A D − A B = 40 − 30 = 10  cm BD = AD - ...

  ⚡ Surface Charge Density After Contact – Electrostatics | JEE Physics | Doubtify JEE 📌 Question: Two metal spheres of radius R and 3R have the same surface charge density σ . They are brought in contact and then separated . After separation, let the surface charge densities be σ₁ (for smaller sphere) and σ₂ (for larger sphere). What is the ratio σ₁ / σ₂ ? 🖼️ Question Image:

  ⚖️ Tension in Strings in Orbiting Satellite – Electrostatics in Space | JEE Physics | Doubtify JEE 💡 Question: Two identical small bodies each of mass = m and charge = q are suspended from two strings of length = l from a fixed point. The system is taken inside an orbiting artificial satellite . 👉 Question: What is the tension in the strings inside the satellite? 🖼️ Question Image: