Introduction to Electronics Test Flashcards

Question

Compare smaller wires and larger wires.

Answer 1

Smaller wires always have greater resistance than larger ones. This is because there is less room for current to flow through. When a wire is smaller, the electrons have less room to go through the wire. With less room, they bounce and rub off each other easier. This bouncing and rubbing produces friction, or resistance. In larger wires, there is more room. Therefore, electrons flowing bump and collide into each other less easily. Therefore, there is less friction, or resistance. The size of the diameter of the wire accommodates certain level of electron flow To many electrons for too thin of a wire will make it disintegrate

Answer 2

The area of a wire is the area of its cross-section. This is calculated by the typical area of a circle, A=πr2. The area is specified in CM, circular MIL. A circular mil is a unit of area equal to that of a 1-mil-diameter circle. The CM area of a wire is the square of the mil diameter.

Answer 3

Feet per pound is the number of feet that a wire gauge will give you per 1lb of weight. For example, being that the wire of AWG 4 is the largest wire, it is also the heaviest. Therefore, it takes only 7.918 feet of wire to weigh 1lb. Meanwhile, AWG 40 is the smallest wire. Therefore, it takes 34,364 feet of wire to weigh 1lb. Feet per pound is a good measure to determine the weight of wire which will be used if the number of feet of the wire needed is known. Good with considering the weight it will put on the structure

Answer 4

Ohms per 1000 ft is a measure of the resistance of a wire. This can be used to determine the electrical resistance of a wire. The longer the wire, the longer the distance. So with longer distance, there are more electrons bumping into each other as well as the walls of the wire. This creates friction and heat, which creates resistance. With greater resistance, this diminishes current capacity. If the wire is shorter in length, this makes less resistance. If the wire is longer in length, this creates greater resistance. Thickness of wire also matters

Answer 5

The current capacity of a wire is the amount of current which a wire can safely carry. Larger wires, being able to accomodate more electrons, since it's larger, can carry much more current through them than smaller wires. If the amount of current that a wire carries exceeds its current capacity, the wire may overload and melt and can cause a fire. Therefore, it is a fire safety hazard to exceed this rating and is very dangerous.

Answer 6

In electronics, the standard size of wires used for breadboards are AWG 22. Since electronics normally deal with low voltage and low current circuits, current flowing through normally does not exceed 1 amperes. Normally the current is somewhere in the milliampere range.

Answer 7

The minimum amount of voltage required to light the LED is called the forward voltage

Answer 8

Power rails are the horizontal rows on the breadboard The gutter or ravine is the middle part in the breadboard

Answer 9

Machines all operate using the same basic power source: the movement of electrons. The three basic principles for this tutorial can be explained using electrons, or more specifically, the charge they create: Voltage is the difference in charge between two points. Current is the rate at which charge is flowing. Resistance is a material's tendency to resist the flow of charge (current). So, when we talk about these values, we're really describing the movement of charge, and thus, the behaviour of electrons.

Answer 10

A circuit is a closed loop that allows charge to move from one place to another. Components in the circuit allow us to control this charge and use it to do work.

Answer 11

Georg Ohm was a Bavarian scientist who studied electricity. Ohm starts by describing a unit of resistance that is defined by current and voltage.

Answer 12

When describing voltage, current, and resistance, a common analogy is a water tank. In this analogy, charge is represented by the water amount, voltage is represented by the water pressure, and current is represented by the water flow. So for this analogy, remember: Water = Charge, Pressure = Voltage, Flow = Current Voltage is like the pressure created by the water. The pressure at the end of the hose can represent voltage. The water in the tank represents charge. The more water in the tank, the higher the charge, the more pressure is measured at the end of the hose. We can think of this tank as a battery, a place where we store a certain amount of energy and then release it. If we drain our tank a certain amount, the pressure created at the end of the hose goes down. We can think of this as decreasing voltage, like when a flashlight gets dimmer as the batteries run down. There is also a decrease in the amount of water that will flow through the hose. Less pressure means less water is flowing, which brings us to current.

Answer 13

We can think of the amount of water flowing through the hose from the tank as current. The higher the pressure, the higher the flow, and vice-versa. With electricity, we measure the amount of charge flowing through the circuit over a period of time. In electrical terms, the current through the narrower hose is less than the current through the wider hose. If we want the flow to be the same through both hoses, we have to increase the amount of water (charge) in the tank with the narrower hose. This increases the pressure (voltage) at the end of the narrower hose, pushing more water through the tank. This is analogous to an increase in voltage that causes an increase in current. Now we're starting to see the relationship between voltage and current. But there is a third factor to be considered here: the width of the hose. In this analogy, the width of the hose is the resistance. This means we need to add another term to our model: Water = Charge (measured in Coulombs) Pressure = Voltage (measured in Volts) Flow = Current (measured in Amperes, or "Amps" for short)

Answer 14

An ampere is defined as 6.241*10^18 electrons (1 Coulomb) per second passing through a point in a circuit.

Answer 15

It stands to reason that we can't fit as much volume through a narrow pipe than a wider one at the same pressure. This is resistance. The narrow pipe "resists" the flow of water through it even though the water is at the same pressure as the tank with the wider pipe. In electrical terms, this is represented by two circuits with equal voltages and different resistances. The circuit with the higher resistance will allow less charge to flow, meaning the circuit with higher resistance has less current flowing through it.

Answer 16

Electricity wants to flow from a higher voltage to a lower voltage. This is exactly like the balloon: the pressurized air in the balloon wants to flow from inside the balloon (higher pressure) to outside the balloon (lower pressure). If you create a conductive path between a higher voltage and a lower voltage, electricity will flow along that path. And if you insert something useful into that path like an LED, the flowing electricity will do some work for you, like lighting up that LED. Every source of electricity has two sides.

Answer 17

Electrical sources are like pumps. Pumps always have two sides, an outlet that blows something out, and an inlet that sucks something in. Batteries and generators and solar panels work the same way. Something inside them is hard at work moving electricity towards the outlet (the positive side), but all that electricity leaving the device creates a void, which means that the negative side needs to pull electricity in to replace it.

Answer 18

In a circuit, a load is any component that consumes electrical energy and converts it into another form, such as light, heat, or motion.

Answer 19

if you connect a wire directly from the positive to the negative side of a power supply, you'll create what is called a short circuit. This is a very bad idea. This seems like the best possible circuit, so why is it a bad idea? Remember that electrical current wants to flow from a higher voltage to a lower voltage, and if you put a load into the current, you can do something useful like light up an LED. If you DO have a load in the current, the current flow through your circuit will be limited to that which your device consumes, which is usually a very small amount. However, if you DON'T put anything in to restrict the current flow, there won't be anything to slow down the current, and it will try to be infinite! Short circuits can steal all the power from the rest of your circuit

Answer 20

An electronics breadboard (as opposed to the type on which sandwiches are made) is actually referring to a solderless breadboard. These are great units for making temporary circuits and prototyping, and they require absolutely no soldering. - if it is solderless, it is a unpermanenet connection which is a huge advantage

Answer 21

Prototyping is the process of testing out an idea by creating a preliminary model from which other forms are developed or copied, and it is one of the most common uses for breadboards.

Answer 22

the tops of the metal rows have little clips that hide under the plastic holes. These clips allow you to stick a wire or the leg of a component into the exposed holes on a breadboard, which then hold it in place. vertical rows on a breadboard

Answer 23

Node: a representation of an electrical junction between two or more components These nodes represent the wires between components

Answer 24

Some amount of current will flow through every path it can take to get to the point of lowest voltage (usually called ground).

Answer 25

In series, have the same current but the voltage is divided There's only one way for the current to flow in the above circuit. Starting from the positive terminal of the battery, current flow will first encounter R1. From there the current will flow straight to R2, then to R3, and finally back to the negative terminal of the battery. Note that there is only one path for current to follow. These components are in series.

Answer 26

If components share two common nodes, they are in parallel. Where series components all have equal currents running through them, parallel components all have the same voltage drop across them

Answer 27

Voltage drop: the reduction in voltage in an electrical circuit between the source and the load

Answer 28

Variable resistor Varibale voltage divider The voltage is divided proportionate to the resistance between the middle pin and the ground pin Like a resistor whose level of resistance can be changed (it can make electrons travel fast, slow, or not at all) Think of a river with two paths. The potentiometer has a wiper, which acts as a branch to control the amount of water flowing through one part of the river, while the rest of the water continues to flow through a different bath → the path represents a parallel circuit and the water represents electrons By changing the position of the wiper, you change the movement of electrons Potentiometers are good because, sometimes, without the limit f electron flow, you can burn out the LED The potentiometer regulates the voltage coming from the battery by "resisting" the current as the knob turns. A potentiometer is often called a variable resistor because the voltage "varies" depending how much the knob is turned.

Answer 29

Allows current to flow in only one direction Hence, in a circuit with an LED, the LED will only turn on if the diode is placed correctly

Answer 30

Rectifier diodes are used to converting alternating current (AC) to direct current (DC) A rectifier is a circuit that converts alternating current (AC) to direct current (DC). This conversion is critical for all sorts of household electronics. AC signals come out of your house's wall outlets, but DC is what powers most computers and other microelectronics.

Answer 31

Current passing through a diode can only go in one direction, called the forward direction. Current trying to flow the reverse direction is blocked. They're like the one-way valve of electronics.

Answer 32

They're like the one-way valve of electronics. If the voltage across a diode is negative, no current can flow, and the ideal diode looks like an open circuit. In such a situation, the diode is said to be off or reverse biased. As long as the voltage across the diode isn't negative, it'll "turn on" and conduct current. Ideally a diode would act like a short circuit (0V across it) if it was conducting current. When a diode is conducting current it's forward biased (electronics jargon for "on"). Every diode has two terminals -- connections on each end of the component -- and those terminals are polarized, meaning the two terminals are distinctly different. It's important not to mix the connections on a diode up. The positive end of a diode is called the anode, and the negative end is called the cathode. Current can flow from the anode end to the cathode, but not the other direction.

Answer 33

Surface mounting: Surface mounting, or Surface Mount Technology (SMT), is a method of attaching electronic components directly to the surface of a printed circuit board (PCB) using solder, rather than through holes

Answer 34

The longer leg on the LED is the anode (positive side) Current flows from the anode to the cathode and NEVER the opposite direction More current equals more light It is important to limit the amount of current flowing to the LED by using resistors because too much current will cause the LED to destroy itself

Answer 35

Polarity indicates whether or not a circuit component is symmetric or not LEDs, being diodes, will only allow current to flow in one direction → when there is no current, there is no light polarity refers to the presence of two distinct and opposite poles, often used to describe the direction of electrical current flow or the orientation of components in a circuit, where one pole is positive and the other is negative. Some electronic components, like capacitors and diodes, are polarized, meaning they have a specific orientation (positive and negative terminals) that must be respected when connecting them to a circuit. Other components, like resistors, are non-polarized, meaning they can be connected in either direction without causing damage or malfunction.

Answer 36

Surface mount LEDs (tiny ones) Through hole LEDs The longer terminal is the anode The flat side of the LED is the cathode side

Answer 37

Kind of like a battery, but it stores energy in a different way; it can not store as much energy as a battery but it can charge and release energy much faster A two-terminal, electrical component Fundamental component to circuits Different sizes (different amounts of capacitance/ the capacity to store charge) What is special about capacitors is their ability to store energy

Answer 38

The standard unit of capacitance is a farad Even 0.001F (1mF) is a big capacitor The curved line means that the capacitor is polarized, meaning that it is probably an electrolytic capacitor (An electrolytic capacitor is a type of capacitor that uses an electrolyte (a liquid or gel with a high concentration of ions) to achieve a larger capacitance than other capacitor types)

Answer 39

It can be used to smooth out fluctuating voltages → water tank analogy If you have a hose pouring water into a tank with a hole, water will come out of the tank after it is filled and the hose is turned off. Eventually, though, it will run out of water and stop releasing water too. THe capacitor acts as the water tank Capacitors are useful in electronic circuits for storing energy, filtering signals, smoothing voltage, and decoupling power supplies (mkaing them independant), among other applications

Answer 40

A capacitor is made of two metal plates, with a dielectric in between (like a sandwich) One of the plates has electrons, while the other doesn't, creating a magnetic field that keep the metal pieces draw to each other, but NOT touching The electrons cannot be transferred from one metal plate to the other through the insulating dielectric At one point, one of the capacitor plates will be so full that it will repel any other electrons coming towards it → this is when you can not the capacitance (farads) When the circuit is created, the electrons will finally have another place to go, causing them to leave their current metal plate (discharge) and, very quickly, move to the other metal plate This current travels rapidly and does not last → it is like the zap for the fly zapper

Answer 41

a tool for measuring voltage resistance, and current

Answer 42

Nodal analysis → a mode of determining the voltage

Answer 43

Parallel Parallel circuits draw more current because adding more paths (resistors in parallel) decreases the total resistance, and according to Ohm's Law (V=IR), a lower resistance with the same voltage results in a higher current

Answer 44

Resistors resist electrical current (limit the flow of electrons) They have a never changing electrical Important so that there is not too much current Resistors have four or five bands The gold or silver band has to be on the right → it is the tolerance band (it is on the right so that you can read the band) With a five-band resistor, the fourth band becomes the multiplier With four bands, the third band is the multiplier

Answer 45

Conventional flow says that electrons move from the positive to the negative Actually, however, the electron flow is actually from negative to positive Either way, it does not matter as long as we all use the same conventional method because either way there is still a flow of electrons

Answer 46

A pushbutton is a mechanical device that allows contact between two terminals A pushbutton’s 4 terminals are always connected when you press the button Otherwise, the two terminals vertical are connected always

Answer 47

Current capacity, also known as ampacity, is the maximum amount of electrical current a conductor (like a wire or cable) can safely carry without exceeding its temperature rating

Answer 48

In this forward-biased state, the diode's resistance is very low, almost like a wire, allowing a large current to flow with only a small voltage drop. Ideal vs. Real: Ideally, a diode would act like a short circuit (0V across it) when conducting. However, in reality, there's a small voltage drop (around 0.3V for germanium and 0.7V for silicon diodes) across the diode when it's conducting. Short Circuit Analogy: Because the voltage drop across a conducting diode is so small compared to the voltage source, it can be considered a short circuit in many practical circuit analyses. Reverse Bias: Conversely, when a diode is reverse biased (negative voltage across it), it acts like an open circuit, blocking current flow.

Answer 49

Yes, a diode exhibits high resistance in one direction (reverse bias) and low resistance in the other (forward bias), allowing current to flow primarily in one direction. Here's a more detailed explanation: Forward Bias: When a diode is forward biased (positive voltage on the anode, negative on the cathode), it acts like a low-resistance path, allowing current to flow relatively easily. Reverse Bias: When a diode is reverse biased (positive voltage on the cathode, negative on the anode), it acts like a high-resistance path, blocking current flow. Ideal Diode: In an ideal scenario, a diode would have zero resistance in the forward direction and infinite resistance in the reverse direction. Real-World Diode: In reality, a diode has a small but measurable resistance in the forward direction and a very high resistance in the reverse direction, but it still functions as a one-way switch for current.

Answer 50

Charging and Discharging: When a rectifier circuit (which converts AC to DC) produces a pulsating DC voltage, a capacitor placed in parallel with the load (the device using the power) will charge up as the voltage rises. Storing Energy: The capacitor stores electrical energy as it charges, acting like a temporary reservoir. Discharging: When the voltage from the rectifier drops, the capacitor discharges, releasing the stored energy to maintain a more constant voltage to the load. Ripple Reduction: This continuous charging and discharging process effectively "fills in" the gaps between the peaks of the rectified waveform, reducing the voltage ripple and making the output DC voltage smoother. Filtering: This process is often referred to as "filtering" because the capacitor acts as a filter, smoothing out the pulsating DC voltage into a more stable and usable form. Protection: Capacitors also protect circuits from voltage spikes by absorbing and storing excess voltage, preventing damage to the circuit and helping to maintain a stable voltage.

Answer 51

Small, electronic switches The control the flow of electrons like a valve They amplify signals, they are used for digital logic

Answer 52

Capacitance is the ability of a component or circuit to collect and store energy in the form of an electrical charge