electronics

electronic components

Electronic components are the parts used in electronic devices such as computers. The components transmit and change electric current. They are made of materials called semiconductors.

electronic signals

Did you ever make a secret code? One way to make a code is to represent each letter of the alphabet by a different number. Then you can send a coded message by writing words as strings of digits. This is similar to how information is encoded using an electric current. The voltage of the current is changed rapidly and repeatedly to encode a message, called an electronic signal. There are two different types of electronic signals: analog signals and digital signals. Both are illustrated in Figure 23.20. A digital signal consists of pulses of voltage, created by repeatedly switching the current off and on. This type of signal encodes information as a string of 0s (current off) and 1s (current on). This is called a binary ("two-digit") code. DVDs, for example, encode sounds and pictures as digital signals. An analog signal consists of continuously changing voltage in a circuit. For example, microphones encode sounds as analog signals.

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electronic devices

Many of the devices you commonly use are electronic. Electronic devices include computers, mobile phones, TV remotes, DVD and CD players, game systems, MP3 players, and digital cameras. All of these devices use electric current to encode, analyze, or transmit information. Consider the computer as an example of an electronic device. A computer contains microchips with millions of tiny electronic components. Information is encoded as 0s and 1s and transmitted as electrical pulses. One digit (either 0 or 1) is called a bit, which stands for "binary digit." Each group of eight digits is called a byte. A gigabyte is a billion bytes thats 8 billion 0s and 1s! Because a computers circuits are so tiny and close together, the computer can be very fast and capable of many complex tasks while remaining small. The parts of a computer that transmit, process, or store digital signals are pictured in Figure 23.22 and described below. They include the CPU, hard drive, ROM, and RAM. The motherboard ties all these parts of the computer together. The CPU, or central processing unit, carries out program instructions. You can learn more about CPUs and how they work by watching the video at this URL: . The hard drive is a magnetic disc that provides long-term storage for programs and data. ROM (read-only memory) is a microchip that provides permanent storage. It stores important information such as start-up instructions. This memory remains even after the computer is turned off. RAM (random-access memory) is a microchip that temporarily stores programs and data that are currently being used. Anything stored in RAM is lost when the computer is turned off. The motherboard is connected to the CPU, hard drive, ROM, and RAM. It allows all these parts of the computer to receive power and communicate with one another.

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types of electronic components

Electronic components contain many semiconductors. Types of components include diodes, transistors, and inte- grated circuits. Each type is described in Table 23.2. Electronic Component Diode Transistor Integrated Circuit (Microchip) Description A diode consists of a p-type and an n-type semicon- ductor placed side by side. When a diode is connected by leads to a source of voltage, electrons flow from the n-type to the p-type semiconductor. This is the only direction that electrons can flow in a diode. This makes a diode useful for changing alternating current to direct current. A transistor consists of three semiconductors, either p- n-p or n-p-n. Current cant flow through a transistor unless a small amount of current is applied to the center semiconductor (through the base). Then a much larger current can flow through the transistor from end to end (from collector to emitter). This means that a transmitter can be used as a switch, with pulses of a small current turning a larger current on and off. A transistor can also be used to increase the amount of current flowing through a circuit. You can learn more about transistors and how they work at this URL: http An integrated circuitalso called a microchipis a tiny, flat piece of silicon that consists of layers of elec- tronic components such as transistors. An integrated circuit as small as a fingernail can contain millions of electronic components. Current flows extremely rapidly in an integrated circuit because it doesnt have far to travel. You can learn how microprocessors are made at this URL:

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semiconductors

A semiconductor is a solid crystalusually consisting mainly of siliconthat can conduct current better than an electric insulator but not as well as an electric conductor. Very small amounts of other elements, such as boron or phosphorus, are added to the silicon so it can conduct current. A semiconductor is illustrated in Figure 23.21. There are two different types of semiconductors: n-type and p-type. An n-type semiconductor consists of silicon and an element such as phosphorus that gives the silicon crystal extra electrons. An n-type semiconductor is like the negative terminal in a chemical cell. A p-type semiconductor consists of silicon and an element such as boron that gives the silicon positively charged holes where electrons are missing. A p-type semiconductor is like the positive terminal in a chemical cell.

instructional diagrams

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questions

electronic signal created by repeated pulses of voltage

a. electronics

b. analog signal

-->  c. digital signal

d. integrated circuit

e. semiconductor

f. diode

g. transistor

Which of the following electric devices uses electric current to encode information?

a. lamp

b. toaster

c. steam iron

-->  d. microphone

tiny flat piece of silicon that contains layers of many electronic components

a. electronics

b. analog signal

c. digital signal

-->  d. integrated circuit

e. semiconductor

f. diode

g. transistor

Which of the following statements about n-type semiconductors is true?

a. They consist of silicon and boron.

b. They contain holes where electrons are missing.

-->  c. They are like the negative terminal of a chemical cell.

d. all of the above

electronic component consisting two semiconductors

a. electronics

b. analog signal

c. digital signal

d. integrated circuit

e. semiconductor

-->  f. diode

g. transistor

Which type of electronic component contains semiconductors?

a. diodes.

b. transistors.

c. integrated circuits.

-->  d. all of the above

Integrated circuits are commonly known as

a. motherboards.

-->  b. microchips.

c. hard drives.

d. CPUs.

electronic signal created by continuous changes in voltage

a. electronics

-->  b. analog signal

c. digital signal

d. integrated circuit

e. semiconductor

f. diode

g. transistor

use of electric current to encode information

-->  a. electronics

b. analog signal

c. digital signal

d. integrated circuit

e. semiconductor

f. diode

g. transistor

Which statement applies to a binary code?

a. It uses continuous changes in voltage.

b. It is used for analog signals.

-->  c. It is based on 0s and 1s.

d. It is an eight-digit code.

electronic component consisting of three semiconductors

a. electronics

b. analog signal

c. digital signal

d. integrated circuit

e. semiconductor

f. diode

-->  g. transistor

material that conducts current better than an insulator but not as well as a conductor

a. electronics

b. analog signal

c. digital signal

d. integrated circuit

-->  e. semiconductor

f. diode

g. transistor

A transistor can be used to increase the amount of current in a circuit.

-->  a. true

b. false

A diode can be used as a switch in an electric circuit.

a. true

-->  b. false

The role of the ROM microchip in a computer is to provide temporary storage.

a. true

-->  b. false

DVDs use digital signals to encode sounds and pictures.

-->  a. true

b. false

Any device that uses electric current is an electronic device.

a. true

-->  b. false

Examples of electronic devices include

a. computers.

b. cell phones.

c. microphones.

-->  d. all of the above

Electronic signals are encoded in electric current by changing the

a. resistance.

b. amperage.

-->  c. voltage.

d. power.

Silicon can conduct current when it contains very small amounts of

-->  a. boron or phosphorus.

b. copper or aluminum.

c. carbon or oxygen.

d. plastic or rubber.

The type of electronic component that can be used to increase the amount of current flowing through a circuit is a

a. diode.

-->  b. transistor.

c. microchip.

d. semiconductor.

Current flows very rapidly through an integrated circuit because the circuit

-->  a. is extremely small.

b. is part of a transistor.

c. contains just one electronic component.

d. is made from an electric conductor such as copper.

The computer microchip that provides temporary storage for programs and data that are currently in use is called

-->  a. RAM.

b. ROM.

c. CPU.

d. none of the above

The role of the motherboard in a computer is to

a. store important information such as start-up instructions.

-->  b. allow other parts of the computer to communicate.

c. provide long-term storage for programs and data.

d. carry out program instructions.

Electronic devices change electric current to other forms of energy.

a. true

-->  b. false

Microphones encode sounds as digital signals.

a. true

-->  b. false

DVDs encode sounds and pictures as analog signals.

a. true

-->  b. false

Electronic components are the parts used in electronic devices.

-->  a. true

b. false

A crystal of pure silicon cannot conduct electricity.

-->  a. true

b. false

Types of semiconductors include diodes and transistors.

a. true

-->  b. false

A microchip may contain millions of electronic components.

-->  a. true

b. false

In a diode, electrons can flow only from the p-type to the n-type semiconductor.

a. true

-->  b. false

TV remotes and CD players are examples of electronic devices.

-->  a. true

b. false

In computers, a byte refers to a single digit (either 0 or 1) of information.

a. true

-->  b. false

diagram questions

No diagram questions associated with this lesson