MCQ in Solid State Devices Part 7 | ECE Board Exam

This is the Multiples Choice Questions Part 7 of the Series in Solid State Devices/Circuits as one of the Electronics Engineering topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Exam Questions in Electronics Engineering field, Electronics Books, Journals and other Electronics References.

MCQ Topic Outline included in ECE Board Exam Syllabi

• MCQs in Semiconductor Fundamentals
• MCQs in Transistor Components
• MCQs in Circuit Analysis and Design
• MCQs in Special Services (Photo Electric, Photo voltaic)

Continue Practice Exam Test Questions Part 7 of the Series

Choose the letter of the best answer in each questions.

301. The name of pure semiconductor material that has an equal number of electrons and holes

A. n-type

B. pure type

C. intrinsic

D. p-type

302. Elements that has four valence electrons are classified as

A. conductor

B. insulator

C. elemental semiconductor

D. compound semiconductor

303. An example of an elemental semiconductor.

A. Germanium (Ge)

B. Gallium Arsenide (GaAs)

C. Gallium Phosphide (GaP)

D. Aluminum Arsenide (AlAs)

304. Which of the following is an example of a compound semiconductor?

A. Gallium Arsenide (GaAs)

B. Gallium Phosphide (GaP)

C. Aluminum Arsenide (AlAs)

D. All of the above

305. Germanium has an atomic number of 32 and an atomic weight of approximately 72 amu. How many electrons, protons and neutrons are there?

A. 32, 32, 40

B. 32, 32, 104

C. 40, 32, 32

D. 40, 32, 104

306. The chemical bond that is present in a crystal lattice of silicon atoms.

A. covalent bond

B. electrovalent bond

C. ionic bond

D. metallic bond

307. The atomic weight of a silicon atom is approximately 28 amu. How many electrons, protons and neutrons does the atom consist?

A. 14, 42, 14

B. 14, 14, 42

C. 42, 14, 14

D. 14, 14, 14

308. What is the total charge at the nucleus of silicon atom?

A. -12e C

B. 12e C

C. -14e C

D. 14e C

309. In materials, what do you call the area that separates the valence band and the conduction band?

A. energy gap

B. forbidden band

C. insulation band

D. A and B are correct

310. At absolute zero temperature, semiconductor acts as

A. an insulator

B. a conductor

C. a semi-insulator

D. usual

311. The electron flow in a semiconductor material is

A. opposite in direction of hole flow

B. the same direction with hole flow

C. the drift current

D. known as the conventional current

312. Typical range of the resistivity of a semiconductor

A. 10^-15 – 10^-18 Ω-cm

B. 10^-5 – 10^-8 Ω-cm

C. 10 – 10^4 Ω-cm

D. 10^8 – 10^15 Ω-cm

313. Chemical bond that is significant in metals

A. ionic bonding

B. electrovalent bonding

C. covalent bonding

D. metallic bonding

314. A semiconductor that is free from impurities

A. intrinsic semiconductor

B. extrinsic semiconductor

C. compensated semiconductor

D. elemental semiconductor

315. The process of adding impurities in a semiconductor material.

A. growing

B. diffusion

C. doping

D. depleting

316. Impurities with five valence electrons.

A. acceptor

B. donor

C. trivalent

D. pentavalent

317. Example of acceptor impurities.

A. pentavalent impurities

B. trivalent impurities

C. tetravalent impurities

D. hexavalent impurities

318. If the substance used in doping has less than four valence electrons, it is known as

A. acceptor

B. donor

C. trivalent

D. pentavalent

319. Commonly used as donor impurities.

A. Antimony (Sb)

B. Arsenic (As)

C. Phosphorus (P)

D. all of the above

320. Example of trivalent impurities.

A. Boron (B)

B. Gallium (Ga)

C. Indium (In)

D. all of the above

321. Donor-doped semiconductor becomes a

A. N-type semiconductor

B. good conductor

C. p-n semiconductor

D. P-type semiconductor

322. What do you call a semiconductor that is doped with both donor and acceptor impurities?

A. double doped semiconductor

B. compensated semiconductor

C. compound semiconductor

D. diffused semiconductor

323. The resistance of a semiconductor is known as

A. bulk resistance

B. intrinsic resistance

C. extrinsic resistance

D. dynamic resistance

324. The most extensively used semiconductor.

A. silicon

B. germanium

C. gallium phosphide

D. gallium arsenide

325. Semiconductor whose electron and hole concentrations are equal.

A. extrinsic semiconductor

B. intrinsic semiconductor

C. compensated semiconductor

D. doped semiconductor

326. Silicon is widely used over germanium due to its several advantages, what do you think is its most significant advantage?

A. abundant

B. cheap

C. temperature stable

D. low leakage current

327. Current flow in a semiconductor that is due to the applied electric field.

A. diffusion current

B. conventional current

C. drift velocity

D. drift current

328. The movement of charge carriers in a semiconductor even without the application of electric potential.

A. diffusion current

B. conventional current

C. drift current

D. saturation current

329. Typically, how much energy is required for a valence electron to move to the conduction band for a doped semiconductor?

A. 0 eV

B. 0.05 eV

C. 1.0 eV

D. 5.0 eV

330. Conduction of electrons in a doped semiconductor happens at

A. conduction band

B. forbidden band

C. valence band

D. nuclei band

331. Theoretically, where does the conduction of holes occur in a doped semiconductor?

A. conduction band

B. forbidden band

C. valence band

D. empty band

332. In energy band diagram of a doped semiconductor, the donor level

A. is near the valence band

B. is near the conduction band

C. is exactly in between the valence and conduction band

D. depends on the amount of doping

333. The acceptor level in a doped semiconductor

A. is near the valence band level

B. is near the conduction level

C. is exactly in between the conduction and valence band

D. will depend on the concentration of doping

334. In a semiconductor material, what will happen to the number of free electrons when the temperature rises?

A. increases

B. decreases exponentially

C. decreases

D. remains the same

335. The electrical resistance of a semiconductor material will ________ as the temperature increases.

A. increase

B. increase exponentially

C. decrease

D. not change

336. The potential required to removed a valence electron

A. valence potential

B. threshold potential

C. critical potential

D. ionization potential

337. Among the given elements, which is considered as nonmetal?

A. silicon (Si)

B. germanium (Ge)

C. tin (Sn)

D. lead (Pb)

338. A semiconductor that is classified as a metalloid or semi-metal

A. silicon (Si)

B. germanium (Ge)

C. tin (Sn)

D. carbon (C)

339. Semiconductor that is very rare, it only occurs in minute quantities in many metal sulfides

A. silicon (Si)

B. germanium (Ge)

C. tin (Sn)

D. lead (Pb)

340. Compound semiconductors are also known as

A. compensated semiconductors

B. amorphous semiconductors

C. organic semiconductors

D. inner-mettalic semiconductors

341. What semiconductor that is mostly used in devices requiring the emission or absorption of lights?

A. amorphous semiconductor

B. organic semiconductor

C. compound semiconductor

D. elemental semiconductor

342. For high-speed integrated circuit, which semiconductor material given below is best to be used?

A. silicon

B. germanium

C. carbon

D. gallium arsenide

343. How much impurity concentration is needed for a sample of silicon to change its electrical property from a poor conductor to a good conductor?

A. one part per hundred

B. one part per thousand

C. one part per million

D. one part per billion

344. The restriction of certain discrete energy levels in a semiconductor material can be predicted generally by using what model?

A. Bohr model

B. string model

C. wave model

D. particle model

345. Is defined as the energy acquired by an electron moving through a potential of one volt.

A. electron Joules (eJ)

B. electron-potential

C. oxidation potential

D. electron Volt (eV)

346. At room temperature, in a perfect silicon crystal, the equilibrium concentration of thermally generated electrons in the conduction band is about

A. 1.5 x 10^5 per cubic cm.

B. 1.5 x 10^10 per cubic cm.

C. 1.5 x 10^15 per cubic cm.

D. 1.5 x 10^20 per cubic cm.

347. What is the basis in operation of semiconductor photoconductors?

A. EHP generation

B. EHP degeneration

C. EHP optical degeneration

D. EHP optical generation

348. The semiconductor that is used in xerography

A. selenium (Se)

B. gallium phosphide (GaP)

C. cadmium compound

D. organic semiconductor

349. A silicon material has an intrinsic concentration ni=10^10 per cubic centimeter at room temperature. If it is doped with 10^15 antimony atoms per cubic centimeter, what is now the approximate electron concentration at the conduction band?

A. 10^5 electrons

B. 10^10 electrons

C. 10^15 electrons

D. 10^20 electrons

350. When an electron at the conduction band falls back to the valence band it will recombine with the hole. This is known as

A. regeneration

B. reunion

C. combination

D. recombination

Questions and Answers in Solid State Devices

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