92. In Ge or Si, heavy doping approximately corresponds to impurity of magnitude
A. 1 part in 108
B. 1 part in 106
C. 1 part in 105
D. 1 part in 104

---

93. When germanium is doped with pentavalent impurity, the resulting material is
A. p-type semiconductor
B. n-type semiconductor
C. intrinsic semiconductor
D. no longer a semiconductor

---

94. When germanium is doped with trivalent impurity, the resulting material is
A. p-type semiconductor
B. n-type semiconductor
C. intrinsic semiconductor
D. no longer a semiconductor

---

95. A p-type semiconductor is
A. positiviely charged
B. negatively charged
C. electrically neutral
D. not used in semiconductor devices

---

96. An n-type semiconductor is
A. positively charged
B. negatively charged
C. electrically neutral
D. not used in semiconductor devices

---

97. Mobility of electron in a semiconductor
A. decreases as the temperature increases
B. increases as the temperature increases
C. has no effect on conductivity
D. is independent of temperature

---

98. Mobility of charge carrier in a semiconductor depends on
A. recombination rate
B. temperature of the semiconductor
C. resistivity of the semiconductor
D. charge per carrier

---