Question: The most commonly used semiconductor is________________?

• 1. Germanium
• 2. Silicon
• 3. Carbon
• 4. Sulphur

Question: A pentavalent impurity has______________Valence electrons?

• 1. 3
• 2. 5
• 3. 4
• 4. 6

Question: Addition of trivalent impurity to a semiconductor creates many_______________?

• 1. Holes
• 2. Free electrons
• 3. Valence electrons
• 4. Bound electrons

Question: As the doping to a pure semiconductor increases, the bulk resistance of the semiconductor_______________?

• 1. Remains the same
• 2. Increases
• 3. Decreases
• 4. None of the above

Question: A trivalent impurity has______________valence electrons?

• 1. 4
• 2. 5
• 3. 6
• 4. 3

Question: The strength of a semiconductor crystal comes from______________?

• 1. Forces between nuclei
• 2. Forces between protons
• 3. Electron-pair bonds
• 4. None of the above

Question: A semiconductor is formed by ______________bonds?

• 1. Covalent
• 2. Electrovalent
• 3. Co-ordinate
• 4. None of the above

Question: The resistivity of a pure silicon is about _______________?

• 1. 100 O cm
• 2. 6000 O cm
• 3. 3 x 105 O m
• 4. 6 x 10-8 O cm

Question: When a pentavalent impurity is added to a pure semiconductor, it becomes________________?

• 1. An insulator
• 2. An intrinsic semiconductor
• 3. p-type semiconductor
• 4. n-type semiconductor

Question: An n-type semiconductor is______________?

• 1. Positively charged
• 2. Negatively charged
• 3. Electrically neutral
• 4. None of the above