Electronics 2

Question 1

Direct current DC

Answer 1

A current that flows only in one direction in a conductor, delivered by a battery.

Question 2

Alternating current AC

Answer 2

A current that changes direction (moves back and forth) many times a second as if moves in a conductor. Household electrical outlets, in North America AC is 60Hz per second

Question 3

Resistors

Answer 3

Not all components within and electrical circuit require the same voltage. There’s also times it’s useful to be able to raise or limit current in a circuit in order to control certain functions (like stereo volume)

Question 4

Fixed resistor

Answer 4

Fixed resistance

Question 5

Variable resistors

Answer 5

(Rheostats or potentiometers) have resistances that can be changed

Question 6

Potentiometers

Answer 6

Useful in changing voltage drops across a component in a circuit. Like volume control

Question 7

Rheostats

Answer 7

Useful in changing the current in a circuit and can be used as light dimmers or to control speed of small motorized devices. Uses colored band system to determine ohms

Question 8

Fuses

Answer 8

Thin wires that melt when current exceeds a prescribed amount, preventing further electrical flow.

Question 9

Circuit breakers

Answer 9

Some function as fuses but can be reused multiple times. Respond more slowly to increase in current than fuses, more expensive

Question 10

Capacitor

Answer 10

AKA condensers, electrical storage units. Two metal conducting plates with very thin insulator (dielectric) between

Question 11

Capacitive Reaistance

Answer 11

Capacitors opposition to the flow of current, measured in ohms. Inversely proportionate to AC signal

Question 12

Capacitance

Answer 12

Ability of the capacitor to store charge, represented by letter C, unit of measurement farad

Question 13

Semiconductors

Answer 13

Elements with 4 electrons in valence shell. Silicon and germanium

Question 14

Doping

Answer 14

Impurities added to semiconductors crystalline structure

Question 15

N-type material

Answer 15

“Doping” silicon with phosphorus, arsenic, or antimony, which have 5 electrons. So when bonded a free electron is able to migrate throughout the crystal. Electrically neutral but able to conduct

Question 16

P-type material

Answer 16

Silicon doped w/ element w/ 3 electrons in valence shell. Leaving a “hole”, creating overall positive charge

Question 17

Diode

Answer 17

P-type and N-type are joined. Current can pass easily in one direction but I blocked in the opposite direction.

Question 18

Forward-biased

Answer 18

Current can only flow one direction so P-type must be connected to battery’s positive terminal and N-type to negative terminal

Question 19

Reverse biased

Answer 19

Reverse diode connection, electrons move away from junction and current flow stops

Question 20

Rectification

Answer 20

Conversion of AC to DC

Question 21

Transistors

Answer 21

Known as solid-state device, can be used as electrical switch, amplifier, current regulator. Computer logic operations

Question 22

Magnetic field

Answer 22

Created by moving charges

Question 23

Inductors

Answer 23

Resist change in current flow measured in henries, L symbol