The energy band gap ($E_g$) varies depending on the material:
For insulators, $E_g$ is positive and large.
For semiconductors, $E_g$ is positive and small.
For conductors, $E_g$ can be effectively zero or negative, as the valence and conduction bands overlap.
Differentiate between interference and diffraction of light. Explain qualitatively the diffraction phenomenon of light by a single slit. Light of 6000 Ã… wavelength is incident normally on a single slit of width \( 3 \times 10^{-4} \, \text{cm} \). Find out the angular width of the central maxima.
Explain the energy bands in solids.
Match List-I with List-II\[\begin{array}{|c|c|} \hline \textbf{Provision} & \textbf{Case Law} \\ \hline \text{(A) Strict Liability} & \text{(1) Ryland v. Fletcher} \\ \hline \text{(B) Absolute Liability} & \text{(II) M.C. Mehta v. Union of India} \\ \hline \text{(C) Negligence} & \text{(III) Nicholas v. Marsland} \\ \hline \text{(D) Act of God} & \text{(IV) MCD v. Subhagwanti} \\ \hline \end{array}\]
Match Fibre with Application.\[\begin{array}{|l|l|} \hline \textbf{LIST I} & \textbf{LIST II} \\ \textbf{Fibre} & \textbf{Application} \\ \hline \hline \text{A. Silk fibre} & \text{I. Fire retardant} \\ \hline \text{B. Wool fibre} & \text{II. Directional lustre} \\ \hline \text{C. Nomex fibre} & \text{III. Bulletproof} \\ \hline \text{D. Kevlar fibre} & \text{IV. Thermal insulation} \\ \hline \end{array}\]