A uniformly charged ring of radius R has total charge Q. The electric field at a point on its axis at distance R from the center is:
Correct answer: C. kQ/(2√2R²)
- A. kQ/(2R²)
- B. kQ/(√2R²)
- C. kQ/(2√2R²)
- D. Zero
Explanation
For a charged ring, the electric field on the axis at distance x is E = kQx/(R² + x²)^(3/2). At x = R, E = kQR/(R² + R²)^(3/2) = kQ/(2√2R²). This is a hard-level question due to themathematical derivation.
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Electrostatics describes forces between charges through Coulomb's law, electric fields and field intensity, then uses electric potential to measure energy per unit charge. Capacitors store charge and electrical energy, with capacitance depending on geometry and dielectric material, not simply on the amount of charge present.
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