1. (i) State the function of the rectifier in power supply (ii) What is the importance of determining the Peak-Inverse-Voltage of a diode? (iii) The energy band in which free electrons exist is the (a) First band (b) second band (c) conduction band (d) valence band (b) Electron-hole pairs are produced by (a) recombination (b) thermal energy (c) ionization (d) doping (v) Each atom in a silicon crystal has (a) four valence electrons (b) four conduction electrons (c) eight valence electrons (d) no valence electrons (vi) The current in a semiconductor is produced by (a) electrons only (b) holes only (c) negative ions (d) both electrons and holes (vii) The process of adding an impurity to an intrinsic semiconductor is called (a) recombination (b) doping (c) atomic modification (d) ionization (viii) The depletion region is created by (20) (a) ionization (b) diffusion (c) recombination (d) answers (a), (b), and (c) (ix) The term bias means (a) the ratio of electrons to holes (b) the amount of diode current (c) applied dc-voltage to control the device (d) answers (a), (b), and (c) (x) For a silicon diode, the value of the forward bias voltage typically (a) must be greater than 0.3 V (b) depends on carrier concentration (c) depends on depletion region width (d) must be greater than 0.7 V 2. A Silicon sample is doped with 25x1017 acceptor atoms/cm3. Determine