Which of the following is a semiconductor? MCQ with Answer and Explanation

Explanation:
Photon energy E = hν, where h is Planck's constant, ν is frequency. Thus E ∝ ν. Since c = νλ, E = hc/λ, so E ∝ 1/λ (inversely proportional to wavelength). Amplitude relates to intensity (number of photons), not individual photon energy. Speed is constant (c) in vacuum. Memory aid: 'Higher frequency (shorter wavelength) photons have more energy (e.g., gamma > radio)'. This quantum physics concept is frequently tested in competitive exams. Always use E = hν for photon energy calculations; avoid confusing wave amplitude with photon energy.

Explanation:
Fuse wire must melt easily (low melting point) to break circuit on overload, and have high resistance to produce sufficient heat (I²R). Materials: tin-lead alloy. Copper not used as fuse.

Explanation:
Minimum deviation δ_m for a prism: n = sin[(A + δ_m)/2] / sin(A/2), where A is prism angle, n refractive index. Thus δ_m depends on both A and n. Since n varies with wavelength (dispersion), δ_m also depends on wavelength, but the primary dependencies are A and n. Memory tip: 'δ_m increases with A and n; used to measure n'. This optics formula application is frequently tested in competitive exams. Always recall that minimum deviation occurs when ray passes symmetrically through prism, a key condition for derivation.