Class name Subject Book title Chapter number Content Created at
Class XII Physics Physics Part-II 5 barrier: (3/2)k T = K ≃ 400 keV, which gives T ~ 3 × 10 K. When fusion is achieved by raising the temperature of the system so that particles have ...
Class XII Physics Physics Part-II 5 energy. Heliumisnottheonlyelementthatcanbesynthesizedintheinteriorof a star. As the hydrogen in the core gets depleted and becomes helium, the core...
Class XII Physics Physics Part-II 5 (b) If both the number of protons and the number of neutrons are conserved in each nuclear reaction, in what way is mass converted into energy (or ...
Class XII Physics Physics Part-II 5 energy per nucleon is nearly constant, about 8 MeV/nucleon. 8. Energies associated with nuclear processes are about a million times larger than che...
Class XII Physics Physics Part-II 5 of a nucleus determined by electron scattering is found to be slightly different from that determined by alpha-particle scattering. This is because...
Class XII Physics Physics Part-II 5 light nuclei. This ratio increases to about 3:2 for heavy nuclei. (More neutrons are required to overcome the effect of repulsion among the protons...
Class XII Physics Physics Part-II 5 + d is defined by Q = [ mA+ m –bm – C ]c d where the masses refer to the respective nuclei. Determine from the given data the Q-value of the follow...
Class XII Physics Physics Part-II 5 constant (i.e. independent of A). Reprint 2026-27
Class XII Physics Physics Part-II 6 Chapter Fourteen SEMICONDUCTOR ELECTRONICS: MATERIALS,DEVICES AND SIMPLE CIRCUITS 14.1 I NTRODUCTION Devices in which a controlled flow of electron...
Class XII Physics Physics Part-II 6 work on the principle of vacuum tubes are being replaced by Liquid Crystal Display (LCD) monitors with supporting solid state electronics.Muchbefor...
Class XII Physics Physics Part-II 6 etc. 324 Most of the currently available semiconductor devices are based on elemental semiconductors Si or Ge and compound inorganic semiconductors...
Class XII Physics Physics Part-II 6 on the valence band electrons can move freely into it. This is the case with metallic conductors. If there is some gap between the conduction band ...
Class XII Physics Physics Part-II 6 of 4N energy states, called the conduction band, is completely Reprint 2025-26te zero. Physics The lowest energy level in the conduction band is sh...
Class XII Physics Physics Part-II 6 possible. Note that the energy gap is so large that electrons cannot be excited from the valence band to the conduction band by thermal excitation....
Class XII Physics Physics Part-II 6 lattice spacing a equal arisesatlowtemperatures.Asthetemperatureincreases, to 3.56, 5.43 and 5.66 Å. more thermal energy becomes available to these...
Class XII Physics Physics Part-II 6 towards negative potential giving the hole current, Ih. The total current, I is thus the sum of the electron current I and the hole current I : e h...
Class XII Physics Physics Part-II 6 same lattice structure. Why is C insulator while Si and Ge intrinsic semiconductors? E Solution The 4 bonding electrons of C, Si or Ge lie, respect...
Class XII Physics Physics Part-II 6 now discuss how the doping changes the number of charge carriers (and hence the conductivity) of semiconductors. Si or Ge belongs to the fourth gro...
Class XII Physics Physics Part-II 6 an atom in the neighbourhood may jump to fill this vacancy, leaving a vacancy or hole at its own site. Thus thehole is available for conduction. No...
Class XII Physics Physics Part-II 6 impurities (ED) and acceptor impurities (E A also exist. In the energy band diagram of n-type Si semiconductor, the donor energy level E is slightl...
Class XII Physics Physics Part-II 6 a group IV element but it is a metal because the energy gap in its case is 0 eV. FIGURE 14.9 Energy bands of (a) n-type semiconductor at T > 0K, (b...
Class XII Physics Physics Part-II 6 drift. We know that in an n-type semiconductor, the r p s n concentration of electrons (number of electrons per unit volume) is more . n compared t...
Class XII Physics Physics Part-II 6 negative charge develops. Due to this field, an electron on p-side of the junction moves to n-side and a hole on n-side of the junction moves to p-...
Class XII Physics Physics Part-II 6 Å) and hence X continuous contact at the atomic level will not be possible. The junction E will behave as a discontinuity for the flowing charge ca...
Class XII Physics Physics Part-II 6 only slightly below the equilibrium value, and only a small number of carriers in the material—those that happen to be in the uppermost energy leve...