Charges q and −q are placed at points A and B a distance 2L apart. C is midpoint between A and B. Work done in moving charge +Q along semicircle CRD as shown in figure is: [Diagram: Image]
Physics · Electrostatic · Electric Potential & Potential Energy
AIPMT 2007 NEET Previous Year

Question

Charges q and −q are placed at points A and B a distance 2L apart. C is midpoint between A and B. Work done in moving charge +Q along semicircle CRD as shown in figure is: [Diagram: Image]

G1 Physics · Accepted Answer

Step 1: Electric work depends only on endpoint potentials, W = Q(Vᴅ − V𝒸). Step 2: Compute potentials from fixed charges at C and D by V = kΣ(qᵢ/rᵢ), using distances shown in original diagram. Step 3: The source solution gives W = −qQ/(6πε₀L) for selected path.