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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 does current divided by resistance equal?
Only those with a weak understanding of electricity believe that the equation, I = E/R, is derived from Ohm's Law. In fact the equation is derived from the definition of the ohm, and not from Ohm's Law! Those who believe that this equation comes from Ohm's Law are demonstrating a fundamental misunderstanding of that so-called 'law'.
Ohm's Law essentially states that 'the ratio of voltage to current is constant for variations in voltage'. No mention of the ohm, and no mention of an equation! If you were to plot a graph of current against voltage for different values of voltage, you will find that very few conductors or other electrical devices produce a straight-line graph; the overwhelming majority produce a curve. So 'linear' or 'ohmic' conductors obey Ohm's Law, whereas 'non-linear' or 'non-ohmic' conductors and devices do NOT! An incandescent lamp, for example, does NOT obey Ohm's Law because its resistance constantly changes as the voltage applied across it changes.
However, the equation R = V/I, which is derived from the definition of the ohm, applies to any circuit for any specified value of voltage, whether that circuit obeys Ohm's Law or not.
If voltage constant when the current increases what does the resistance do?
In an electric circuit, ratio of current and voltage is constant which is known as the resistance of the circuit. If voltage or current is to be changed the resistance has to be changed. You cannot keep an invariable resistance in the circuit and increase current while keeping voltage as constant.Hence to vary the voltage or current in a circuit different equipments like rheostat,potentiometer are used.
How should a ammeter and voltmeter be connected in series?
no. you want to measure across the desired circuit segment. whether you are measuring voltage drop or current.
A unipolar waveform is a type of electrical signal where the voltage fluctuates between a zero reference point and a positive or negative peak, but does not oscillate around zero. This means that the waveform only exists above or below the zero line, typically remaining positive or negative throughout its cycle. Unipolar waveforms are commonly used in digital circuits and signal processing, where a clear distinction between two states is needed, such as in pulse-width modulation. Examples include certain types of pulse signals and power supply outputs.
What is maximum forward current in case of diodes?
the maximum amount of current that a forward-biased diode can withstand before burning out or being seriously degraded.
What is meant by atenuation in fiber optics?
Attenuation in fiber means 'loss of optical power' suffered by the optical signal in fiber itself.
What happens to the current through a component as the voltage increases?
In any conductor, increased current flow will result in voltage drop. This won't have any effect until you reach about 5% of the circuit voltage, at which point your efficiency declines. If the increased current trips the breaker, then your Voltage will be 0
For reference: Vd= (1.732 x K x I x L) / cmil
Vd is Voltage drop in Volts
1.732 is sq rt of 3 for three phase circuits. For two phase or single phase circuits use 2
K is resistance in Ohms of 1cmil, 1ft of conductor.
K=12.9 for copper conductors, 21.2 for aluminum, both at 75 deg C
I is the current (hence, the more current, the more voltage drop)
L is the length of the conductor
cmil is the wire size, or more accurately, cross-sectional area of the conductor
What PIV rating must a diode have to be used in a rectifier with a peak output voltage of 50 V?
100, or twice to expected output. This is because, on the alternate half-cycle, the line goes to the alternate peak-peak voltage away from the charged capacitor. In this case, that will be 100.
However, in terms of actual rating, you must always provide a margin of safety. I would use a 200 volt diode in this application, to allow for variance in limits and transient response.
An ammeter is an instrument which is used for measurement of current flowing in any circuit
V = IR
Voltage = Current * Resistance
so
9 = 0.25 * R
Hence R =36 Ohms
What is the output voltage of a 400 watt mtal halide?
According to Sylvania, their 400w lamps reach a maximum surface temperature of around 750F. This seems to be universal of all HID lamp types.
How can you convert T flip flop into D flip flop?
D Flip flop which have driven the output as the given input there is no change in the I/O.
But in the case of T-Flipflop the output is inverted to the given input .i.e complement of the input is output.
Thank you i am meganathan...
When can voltage be induced but not current?
"Induced" is the verb you are looking for. A current is induced in the secondary circuit by the current in the first changing, provided both conductors are close enough for the driving current's electro-magnetic field to enclose the second conductor.
Note that word "changing". Direct current produces a field but that remains constant and does not induce a secondary current, as a.c. does.
Efficiency of class C amplifier is approximately 100%.
What are 3 advantages transistors have over valves?
Transistor-transistor logic (TTL) is a class of digital circuits built from bipolar junction transistors (BJT) and resistors. It is called transistor-transistor logic because both the logic gating function and the amplifying function are done by transistors.
To know about the advantages of TTL logic family, one should have a basic idea about RTL, DTL etc. Diode logic (DL) uses diodes to implement logical functions like AND and OR. But the disadvantage is that it can not perform NOT operation. As AND and OR are not complete functions by themselves, they can not perform several logic functions without NOT. Hence, there was a need for some device which can perform a NOT function as diodes can not. That device is a transistor. Then came the DTL which uses a transistor along with diodes. As a transistor can act as an inverter, NAND (NOT-AND) & NOR (NOT-OR) operations can be performed. But this logic uses several diodes which will slow down its operation. Due to the delay offered by them, the logic levels may sometimes change i. e. 0 t0 1 or 1 to 0. Then came TTL. This logic uses a multi emitter transistor, a transistor with many emitter terminals. As every emitter is nothing but a diode, this logic eliminates the use of all diodes. This is the major advantage. As transistor becomes ON and OFF much rapidly than a diode, switching time will be faster.
TTL, or Transistor-transistor logic replaced resistor-transistor logic, and used much less power. The TTL family is very fast and reliable, and newer faster, less power-consuming, etc. types are always being developed.
ANSWER: ONE WORD SPEED
If a resistor decreases in value what will happen to the current through the resistor?
If the voltage applied across the resistor remains constant, then as the resistance of the resistor decreases, the current through it will increase. Consider Ohm's Law: E = IR In this formula, in order for 'E' to remain constant as 'R' decreases, 'I' must increase. Another form of Ohm's Law: I = E/R If 'E' remains constant, then the value of the fraction increases as its denominator 'R' decreases.
A wireless LAN or WLAN is a wireless local area network, which is the linking of two or more computers without using wires. WLAN utilizes spread-spectrum or OFDM modulation technology based on radio waves to enable communication between devices in a limited area, also known as the basic service set. This gives users the mobility to move around within a broad coverage area and still be connected to the network. For the home user, wireless has become popular due to ease of installation, and location freedom with the gaining popularity of laptops. Public businesses such as coffee shops or malls have begun to offer wireless access to their customers; some are even provided as a free service. Large wireless network projects are being put up in many major cities. Google is even providing a free service to Mountain View, California and has entered a bid to do the same for San Francisco. New York City has also begun a pilot program to cover all five boroughs of the city with wireless Internet access. A wireless LAN or WLAN is a wireless local area network, which is the linking of two or more computers without using wires. WLAN utilizes spread-spectrum or OFDM modulation technology based on radio waves to enable communication between devices in a limited area, also known as the basic service set. This gives users the mobility to move around within a broad coverage area and still be connected to the network. For the home user, wireless has become popular due to ease of installation, and location freedom with the gaining popularity of laptops. Public businesses such as coffee shops or malls have begun to offer wireless access to their customers; some are even provided as a free service. Large wireless network projects are being put up in many major cities. Google is even providing a free service to Mountain View, California and has entered a bid to do the same for San Francisco. New York City has also begun a pilot program to cover all five boroughs of the city with wireless Internet access.
What are the drawbacks of using amplitude modulation?
1)Lower frequencies, shorter range, smaller bandwidth.
2)More power required because, in amplitude modulation we are transmitting 3 frequencies i.e, carrier, lower side band and higher side band. the carrier have no any information but it required 2/3rd power.
3)The two side bands have same information so there is no need of transmitting the two side bands.
What happens to atoms when cooled?
as the atom cools down it comes back in its orignal shape .it will be in its contracting form
Why do elements like copper conduct electricity so well?
Copper is cheap as compared to silver which is much a better conductor. The number of free electrons(those which have escaped from the shackles of nucleus but roam free in the lattice) is very high in these. Free electrons are the cause for conduction. More free electrons means more conduction
Where is gold located on a circuit board?
gold is applied as a micro-thin layer over the entirety of the circuits to protect them from oxidation.
Gold is not on "the entirety" of the board, just the connector contacts. The rest of the copper traces can either be protected with tin (its cheaper) and/or a "mask" of green insulating varnish.
How does a simple component and continuity tester work?
A continuity tester is sometimes referred to as a "bell set". To make one, procure a battery, an electric bell or buzzer, and some wire. With wire 1, connect one battery terminal to one side of the bell. With wire 2, momentarily connect the other battery terminal to the other side of the bell, and note the buzzer sound. Any time you complete the circuit, you will hear that sound.
Now create these connections: battery+ => wire1 => bell => wire2 => component => wire3 => battery-
If the unknown "component" conducts current, then you will hear the bell, otherwise there is a fault.
