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Electronics Engineering
Electronics Engineering is a branch of engineering that deals with practical applications of electronic components, devices, systems, or equipment. Electronics are devices that operate on low voltage sources, as in electron tubes, transistors, integrated circuits, and printed circuit boards and use electricity as part of its driving force.
24,372 Questions
What are the relationships between current power and resistance?
Power is inversely proportional to resistance.
Ohm's law: Current is voltage divided by resistance
Power law: Power is voltage times current, therefore power is voltage squared divided by resistance.
What are the challenges faced in designing an embedded systems?
The embedded system is a computing system that interacts with the physical world. The challenges that it faces at present are on how to build on top of a non-deterministic system and how to build on top of a non-continuous system.
Describe the effects of reversing all the diodes directions?
If diodes are not istalled in the right direction and an electrrical current applied the diodes may burn out
What is the application of counters?
Counters are a way of measuring amounts. Counters are used to physically show 'how much' especially when teaching children basic math.
What is the value in ohms of a resistor colored red red yellow gold?
Using a resistor color code chart below, you will find that the resistance is calculated this way:
Resistance = (1st Digit x 10 + 2nd Digit) x Multiplier
Hold the resistor with the gold or silver band to the right and read the resistor from the left to the right.
So, in this case, the resistor is: RED RED YELLOW GOLD
Using the formula and resistor color chart found in the link below, the resistance would be:
R = 1st Digit x 10 + 2nd Digit) x Multiplier
R = (RED x 10 + RED) x YELLOW
R = (2 x 10 + 2) x 10,000
R = 22 x 10,000
R = 220,000 ohm (220 K ohms)
Since the final band is gold, the tolerance is 5%
Any circuit that converts binary information into machine readiable form is called sequential circuit
What is the purpose of a blocking capacitor?
At high frequency, capacitor can be considered as
1. Short Circuit in AC analysis.
2. Open Circuit in DC analysis.
{because Xc= 1/(2*f*pi) where f= supply frequency,pi=3.14}
As at high frequencies, in DC analysis, capacitor will be open circuited & can block the DC signal while AC signal is allowed to pass through.. Hence, this capacitor will act as a blocking capacitor for DC supply.
Why does adding more resistance result in less current?
As the name implies, resistance resists current. In the mathematical formula, where E is electromotive force (voltage):- I = E/R If you increase the value of R (resistance), then the value of I (current) decreases.
Can 1700 mAh battery replace 250 mAh battery?
In general, no. The charger is designed for a specific battery profile, and it might not be able to properly charge and/or monitor the amount of charge if you put in a different battery.
How long will it take a 1 μF capacitor to completely discharge through a 47 kΩ resistor?
forever. the discharge curve of an RC circuit is exponential and the closer it gets to discharged the slower it discharges. this is true for all values of capacitors and resistors.
What are the advantages of moving coil instrument?
Advantages are:- high sensitivity, uniform scale, very effective and reliable eddy current danping well shelded from any stray magnetic field. Disadvantages are:- very expensive, only suitable for direct current and voltages.
What are the advantages using 3D Radar over 2D Radar?
The three Dimensional maps created a revolution in the field of navigation and medical and also in the engineering field. The advantage of 3D maps are that it can give the idea of all the dimensions and hence better designs can be created by looking at the 3d maps and the conventional maps were not that much informative compared to 3D maps are
What is Class B push-pull amplifier?
When we get amplifier output current for 180 degrees of input. then it's called B class amplifier.
In a push pull class B amplifier one of the two power transistors or other amplifying elements handles the positive half of the waveform and the other element handles the negative half of the waveform.
In practice, push pull audio amplifiers are usually class AB; each power transistor handles slightly more than 180 degrees of input. This minimizes distortion (crossover distortion) when one of the two transistors ceases output and the other takes over.
a relay switch can be used to control one voltage from another(e.g. 24 volt controlling a 120v circuit), or controlling multiple functions and circuits from one voltage switch or location. advantages to relays are that the size of conductor can be greatly reduced with a lower voltage(cost and ease of installation) and consumer convienience(one switch for 100 lights or one photocell controlling an entire parking lots lighting even with a rating of 15 amps)
Compare high level modulation and low level modulation?
IN LOW LEVEL MODULATION THE MODULATING SIGNAL IS APPLIED NEARER THE CARRIER OSCILLATOR N IN HGH LEVEL MODULATION MODULATING SIGNAL IS APPLIED AT OUTPUT OF FINAL POWER AMPLIFIER OR FAR FROM CARRIER OSCILLATOR... IN OTHER WORDS :::: IN HAIGH LEVEL MODULATION THE AF SIGNAL IS APPLIED TO COLLECTOR OR PLATE AS THEIR RESPECTIVE DEVICES..... N IN LOW LEVEL MODULATION AF SIGNAL IS APPLIED AT BASE OR GRID IN TRANSISTOR AND TUBES RESPECTIVILY IN LOW LEVEL MODULATION THE MODULATING SIGNAL IS APPLIED NEARER THE CARRIER OSCILLATOR N IN HGH LEVEL MODULATION MODULATING SIGNAL IS APPLIED AT OUTPUT OF FINAL POWER AMPLIFIER OR FAR FROM CARRIER OSCILLATOR... IN OTHER WORDS :::: IN HAIGH LEVEL MODULATION THE AF SIGNAL IS APPLIED TO COLLECTOR OR PLATE AS THEIR RESPECTIVE DEVICES..... N IN LOW LEVEL MODULATION AF SIGNAL IS APPLIED AT BASE OR GRID IN TRANSISTOR AND TUBES RESPECTIVILY
What colour is the solid copper?
- bare copper wire is copper orange color.
- tinned copper wire is silvery color.
- enamel coated copper magnet wire can come in any color, depending on enamel.
- plastic coated copper hookup wire can come in any color, depending on plastic.
copper wire for household wiring is color coded using plastic coating:
- black - hot 120 VAC
- white - neutral 0 V current return
- green - ground 0 V safety return (no current normally)
- red - hot 120 VAC, opposite phase from black for use in 240 VAC hookups
- etc.
copper wiring for industrial 3-phase power has additional colors, which I won't visit here.
copper wire for electronic use follows an entirely different color code:
- red - positive DC power
- black - DC return
- green - negative DC power, or signal if no negative power
- other colors - signals
don't confuse color codes!
The first DC motor was made by a British scientist William Sturgeon in the year of 1832. The motor he made was the first motor capable of turning machinery.
What are the advantages of optical fiber over waveguide?
much wider bandwidth. Ie, many more signals can be run over the same cable.
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Optical transmission has several advantages over copper wire:
- optical fibre's high bandwidth means that a lot more data can be transmitted faster.
A pair of copper wires (which is what most houses in urban areas use for the initial point of access to the Internet can transmit two telephone calls simultaneously, while a single optical fibre can transmit over 80,000; - glass is cheaper and lighter than copper;
- optical fibre is unaffected by electro-magnetic interference, and so is ideal in electrically "noisy" environments, eg where there is high voltage equipment nearby;
- no electrical current is transmitted down a fibre (glass is a good insulator), so it is suitable in hazardous environments where electrical discharge would dangerous;
- as transmission technology continues to improve, higher and higher bandwidths are possible over the same optical fibre links without having to replace the cables.
What are the main parts of a DC servo motor?
Motor inside and outside movement and non movement material
Why Silicon is used widely as a semiconducting material?
Silicon is abundant in nature as SiO2(sand).
Getting the Si from SiO2 is comparatively easier than other semiconductors like Ge.
And Silicon is a better conductor at room temperature.
valence electron in germanium are in fourth shell whereas on silicon valence electron is in third shell.
germanium valence electron are at higher energy level than silicon .hence germanium valence electron will need smaller amount of energy to escape form the atom due to this germanium more number of electron pair than silicon . hence leakage current is more.
this property makes germanium more unstable at high temperature.
What is the unit of electron current?
Electron current flow is measured in coulombs per second, which is known as amperes.
A coulomb is about 6.242 × 1018 electrons.
What is the advantages and disadvantages of varactor diode?
is basically an electrically controlled variable capacitor
no moving parts need a monitored voltage source to hold the value
temperature sensitive Si based dont work over 100C
variable capacitors in the mechanical adjusted variety work with higher voltages arent voltage spike sensitive and are far more rugged are in picofarad to micro farad range can handle many kilowatts set and forget dont need controls to maintain capacitance arent temperature sensitive can be motor driven for electric control
A: Initially the construction of an FET closely resemble the double diffused bipolar epitaxial transistor Both begins with an n+ substrate n- forming a 4 layer structure. another distinguishing feature is the electrical bonding of the upper most n+ diffusion [source] however with this bonding a parasitic diode in parallel cathode drain to source fortunatelly by virtue the polarity operation is unaffected. All in all FET have higher power, higher voltage rating practically no thermal runaway and a greatly inhibited secondary breakdown characteristics
