Which of the following electromagnetic waves has the highest frequency? MCQ with Answer and Explanation

Explanation:
Beats occur due to interference of two waves with slightly different frequencies (Δf small, typically < 10 Hz for audible beats). The beat frequency is |f₁ - f₂|, causing periodic loudness variation. Same frequency (A, B) produces steady interference (no beats); very different frequencies (D) produce rapid fluctuations not perceived as beats. Memory aid: 'Beats: |f₁ - f₂| small ⇒ audible pulsations; used in tuning'. This wave phenomenon question tests superposition understanding, frequently examined in competitive exams. Always link beat perception to frequency difference magnitude; competitive exams often test qualitative conditions for observable beats.

Explanation:
Most solar cells use silicon (monocrystalline or polycrystalline). Other materials: gallium arsenide, cadmium telluride. Silicon is semiconductor, abundant, efficient. Converts sunlight to electricity.

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).