Please solve all questions. 04. 201 Curstions (3 to 14) by chousing the unly the
ID: 2266905 • Letter: P
Question
Please solve all questions.
04. 201 Curstions (3 to 14) by chousing the unly the covalent2 Exof e a Si, Ga b. Si, Ge AIP. Ge d. None of the above 4. At zero degree kelvin d both a. only free electrons b. only free holes c. both (a) and (b) d. no free carriers al and with v 6,-Hole diffusion current-density becom insic a the gradient of hole concentration b lta b. the hole concentration c. the gradient of electron concentration dn d. electron mobility n-type both (a) and (c ion of a pn junetion pletion (b) and (c) regian is ormed an the metallursical . At thermal equilibrium. the depletion at the metallurgical 8. At contains a. only free electrons b. no charge carriers c. only free holes d. both (a) and (c) carrier a. electron concentration is higher 10- /cm hole concentration is higher either (a) or (b) c. 01 /cm he above citor is found when sity becomes diferent voltage at a pm junction is varied tric field is very high bove d. 12. When the forward voltage of a pn junction increased, the forward current increases a. linearly b. hyperbolically c. exponentially at a electric filed isExplanation / Answer
1. Silicon has 14 electrons
First shell is K shell having 2 electrons
2nd shell is L shell having 8 electrons
3rd shell that is M shell has 4 electrons that result in covalent bonding.
2. Si is an elemental semiconductor whereas GaP is a compound semiconductor.
3. Electrons and holes can exist both in conduction and valence band.
4. At absolute zero that is Zero kelvin semiconductors have no free carrier and the behave as an insulator.
5. Donor atoms has 5 electrons so when they replace the intrinsic semiconductor atoms one extra electron remains free and the semiconductor becomes n type.
6. Diffusion current flows because of concentration gradient therefore A is the correct option.
8. At thermal equilibirium depletion region contains no free carriers.
10. At thermal equilibirium law of mass action is followed which is given by the B.
12.pn junction is a non linear device with exponential dependence of current over the voltage therefore C is correct.