When white light passes through a prism, it disperses into colors because: MCQ with Answer and Explanation

Dispersion occurs because refractive index of glass varies with wavelength (color): n ∝ 1/λ approximately. Since v = c/n, different colors travel at different speeds in glass, causing different refraction angles (Snell's law). Frequency remains constant across media; wavelength changes. Option B is true but not the direct cause; speed difference causes angle difference. Memory tip: 'VIBGYOR: Violet bends most (slowest in glass), red least'. This conceptual question tests understanding of dispersion mechanism, crucial for optics in competitive exams. Always distinguish cause (speed variation) from property (frequency/wavelength).