1. A semiconductor is formed by ........ bonds.
(i) covalent (ii) electrovalent (iii) co-ordinate (iv) none of the above
2. The most commonly used semiconductor is ........
(i) germanium (ii) silicon (iii) carbon (iv) None
3 A semiconductor has generally ........ valence electrons.
(i)2 (ii) 3 (iii)6 (iv) 4
4. The maximum number of electrons which the valence shell of an atom can have is
(a) 6
(b) 8
(c) 18
(d) 2
5. When a pentavalent impurity is added to a pure semiconductor, it becomes ........
(i) an insulator (ii) an intrinsic semiconductor (iii) p-type semiconductor (iv) n-type
semiconductor
6. Addition of pentavalent impurity to a semiconductor creates many ........
(i) free electrons (ii) holes (iii) valence electrons (iv) bound electrons
7. A pentavalent impurity has ........ valence electrons.
(i)3 (ii) 5 (iii)4 (iv) 6
8. An n-type semiconductor is ........ (i) positively charged (ii) negatively charged Electronics (iii)
electrically neutral (iv) none of the above
9. A trivalent impurity has ........ valence electrons. (i)4 (ii) 5 (iii)6 (iv) 3
10. Addition of trivalent impurity to a semiconductor creates many ........ (i) holes (ii) free
electrons (iii) valence electrons (iv) bound electrons
11. A hole in a semiconductor is defined as ........ (i) a free electron (ii) the incomplete part of an
electron pair bond (iii) a free proton (iv) a free neutron
12. As the doping to a pure semiconductor increases, the bulk resistance of the semiconductor ...
