Four equal point charges q sit at the corners of a square of side d. T…

Question

Four equal point charges q sit at the corners of a square of side d. The work needed to assemble this configuration from infinity is

Accepted Answer

C. {'text': '(kq²/d)(4 + 2/√2)', 'label': 'C'}

1. Pairs: 4 sides at distance d (4 pairs) and 2 diagonals at distance d√2 (2 pairs).
2. Total PE = k q²[(4/d) + (2/(d√2))] = (k q²/d)(4 + 2/√2).
3. The work done from infinity equals this PE since the field at infinity does no work.
_Source: NCERT Class 12 Physics Part I, Ch 2 Example 2.4_

Answer

{'text': '(kq²/d)(2 + 1/√2)', 'label': 'A'}

Answer

{'text': '(kq²/d)(4 + √2)', 'label': 'B'}

Answer

{'text': '(kq²/d)(1 + 1/√2)', 'label': 'D'}