Chapter 9: Semiconductors, Diodes, Radio Waves, Computers, Analog & Digital Converters, Information Technology
Multiple Choice Questions Bank
1. A semiconductor material has conductivity that is:
- (a) Very high
- (b) Very low
- (c) Intermediate
- (d) Zero
2. Which element is most commonly used in semiconductor devices?
- (a) Gold
- (b) Silicon
- (c) Silver
- (d) Copper
3. Doping in a semiconductor is done to:
- (a) Increase conductivity
- (b) Reduce conductivity
- (c) Make it an insulator
- (d) Make it a superconductor
4. In a p-type semiconductor, the majority charge carriers are:
- (a) Neutrons
- (b) Holes
- (c) Electrons
- (d) Protons
5. An n-type semiconductor is created by adding:
- (a) Trivalent impurities
- (b) Pentavalent impurities
- (c) Tetravalent impurities
- (d) No impurities
6. A diode allows current to flow:
- (a) In one direction only
- (b) In both directions
- (c) In a circular path
- (d) Alternating directions
7. The main purpose of a diode in electronic circuits is to:
- (a) Amplify signals
- (b) Convert AC to DC
- (c) Store energy
- (d) Generate power
8. A rectifier converts:
- (a) DC to AC
- (b) AC to DC
- (c) AC to AC
- (d) DC to DC
9. When a diode is forward biased, it:
- (a) Blocks current flow
- (b) Conducts current
- (c) Operates as an insulator
- (d) Increases voltage
10. Which type of waves are used in radio communication?
- (a) Sound waves
- (b) Electromagnetic waves
- (c) Light waves
- (d) Ocean waves
11. Radio waves are a part of the:
- (a) Visible spectrum
- (b) Electromagnetic spectrum
- (c) Sound spectrum
- (d) Mechanical spectrum
12. The speed of radio waves in a vacuum is:
- (a) 3 x 10^6 m/s
- (b) 3 x 10^8 m/s
- (c) 300 m/s
- (d) 3 m/s
13. AM in AM radio stands for:
- (a) Amplitude Modulation
- (b) Analog Modulation
- (c) Amplitude Multiplication
- (d) Average Modulation
14. Computers are classified as:
- (a) Digital devices only
- (b) Analog devices only
- (c) Both analog and digital devices
- (d) Neither analog nor digital
15. In a computer, the CPU is responsible for:
- (a) Storage only
- (b) Processing data
- (c) Displaying information
- (d) Powering devices
16. Which type of memory is volatile?
- (a) ROM
- (b) Hard Disk
- (c) RAM
- (d) CD-ROM
17. The binary system used by computers has how many digits?
- (a) 2
- (b) 8
- (c) 10
- (d) 16
18. In binary code, the two digits are represented by:
- (a) 1 and 2
- (b) 0 and 1
- (c) 0 and 2
- (d) 1 and 3
19. The device that converts analog signals into digital signals is called:
- (a) ADC
- (b) DAC
- (c) Amplifier
- (d) Rectifier
20. ADC stands for:
- (a) Analog Digital Calculator
- (b) Analog Digital Converter
- (c) Amplifier Digital Converter
- (d) Analog Data Controller
21. Digital signals are:
- (a) Continuous
- (b) Discrete
- (c) Incomplete
- (d) Repetitive
22. Information Technology (IT) mainly involves:
- (a) Storing and managing data
- (b) Building circuits
- (c) Operating heavy machinery
- (d) Generating electricity
23. The smallest unit of data in a computer is a:
- (a) Byte
- (b) Bit
- (c) Megabyte
- (d) Gigabyte
24. A monitor is an example of a:
- (a) Input device
- (b) Processing device
- (c) Output device
- (d) Storage device
25. What does RAM stand for?
- (a) Read Access Memory
- (b) Random Access Memory
- (c) Read Action Memory
- (d) Rapid Access Module
26. Information in ROM is:
- (a) Temporary
- (b) Lost when power is off
- (c) Permanent
- (d) Modifiable
27. The purpose of an amplifier is to:
- (a) Decrease current
- (b) Increase voltage
- (c) Increase power
- (d) Store energy
28. The primary function of a transistor is to:
- (a) Store data
- (b) Control current
- (c) Measure voltage
- (d) Provide resistance
29. Semiconductors are used in:
- (a) Light bulbs
- (b) Power lines
- (c) Electronic circuits
- (d) Concrete
30. An LED emits:
- (a) Heat
- (b) Sound
- (c) Light
- (d) Vibration
31. The basic function of a computer is to:
- (a) Convert electrical energy
- (b) Perform calculations and store data
- (c) Provide resistance
- (d) Generate light
32. The most basic unit of data is a:
- (a) Byte
- (b) Bit
- (c) Nibble
- (d) Word
33. A software that manages computer hardware is:
- (a) System software
- (b) Application software
- (c) Utility software
- (d) Firmware
34. ROM is:
- (a) Readable and writable
- (b) Read-only
- (c) Writable only
- (d) Temporary
35. Which device is used to connect a computer to the internet?
- (a) Modem
- (b) Monitor
- (c) Printer
- (d) Keyboard
Answer Key
1. (c)
2. (b)
3. (a)
4. (b)
5. (b)
6. (a)
7. (b)
8. (b)
9. (b)
10. (b)
11. (b)
12. (b)
13. (a)
14. (c)
15. (b)
16. (c)
17. (a)
18. (b)
19. (a)
20. (b)
21. (b)
22. (a)
23. (b)
24. (c)
25. (b)
26. (c)
27. (c)
28. (b)
29. (c)
30. (c)