1. Distinguish between intrinsic and extrinsic semiconductors. (4 mks) 2. Explain the effect of temperature on intrinsic semiconductor (4mks) 3. Define doping as used in semiconductors. Then state the type of dopant commo ly used on a semiconductor (4m s) 4. Explain (using conduction band, valance band and forbidden gap band) why a s mall increase in temperature/energy will lead to conduction of semiconductors. mks) 5. Use a diagram to explain how a P-type semiconductor is formed s) (5m 6. Explain V-1 characteristics of pn junction Diode. (6 mks) 7. Draw the V-1 characteristics of a diode with zero cut-in voltage and equivalent res stance of 100Omega Draw the load line if RL is also 100Omega (5 mks) 8. Explain different breakdown mechanisms in PN junction diode . s) (5ml 9. Use the graph of Fig. Q1 to determine the dc resistance levels of a given silicon c ode ati). I_(D)=2mA ii). I_(D)=20mA iiildots V_(D)=-10V

1. Intrinsic semiconductors are pure materials without any impurities, while extrinsic semiconductors are doped with impurities to change their electrical properties.<br /><br />2. As temperature increases, the thermal energy of the lattice vibrations increases, causing more electron-hole pairs to be generated, increasing the intrinsic carrier concentration.<br /><br />3. Doping is the process of adding impurities to a semiconductor to change its electrical properties. Common dopants include phosphorus (n-type) and boron (p-type).<br /><br />4. A small increase in temperature/energy provides enough energy to electrons in the valence band to jump into the conduction band, leading to increased conduction.<br /><br />5. A P-type semiconductor is formed by doping a pure semiconductor with a p-type dopant, such as boron, which creates holes in the semiconductor.<br /><br />6. The V-I characteristics of a PN junction diode show a sharp increase in current for a small increase in voltage, followed by a linear increase. The reverse bias shows a sharp decrease in current.<br /><br />7. The V-I characteristics of a diode with zero cut-in voltage and an equivalent resistance of 100Ω show a linear increase in current with voltage. The load line intersects the diode characteristics at the operating point.<br /><br />8. Breakdown mechanisms in PN junction diodes include Zener breakdown, avalanche breakdown, and thermal breakdown.<br /><br />9. Using the graph of Fig. Q1, the dc resistance levels of a given silicon diode can be determined by finding the voltage and current values at specific points on the graph.