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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 happens when one of three diode is removed from 3 phase full wave rectifier?
A: Then the phase that the diode is remove will not work or Rather get an output
What is the formula for total current in a series circuit?
Current = (Voltage across the circuit) divided by (Total resistance of the circuit).
The current is the same at every point in the series circuit.
Difference between ac dynamo and dc dynamo?
1. AC Dynamo has full rings whereas DC Dynamo has split rings.
2. AC Dynamo produces alternating current whereas DC Dynamo produces direct current.
3. IN AC DYNAMO, CURRENT KEEPS CHANGING EVERY HALF OF A CYCLE WHEREAS IN DC DYNAMO, CURRENT FLOWS IN SAME DIRECTION.
How to convert 100ampere to kva?
Divide by your number of phases 1 or 3 then divide by your Voltage. If its a 3 phase supply Voltage you need to divide by your 3 phase voltage for balanced loads and by your single phase voltage for unbalanced loads requiring a neutral.
How do you work out the secondary voltage in a transformer?
The voltage ratio is the same as the turns ratio for an ideal transformer, and most transformers are close to being ideal. So use the following equation:
Vs/Vp = Ns/Np
No.
Radar use electromagnetic radiation of a much longer wavelength
How can I program 4 x 16 decoder in VHDL?
1st - 2:4 decoder using "enable" :
entity DECODER is
port (A, B, Enable : in std_logic ;
Out : out std_logic_vector(3 downto 0)
);
end DECODER;
architecture ARC.DECODER of DECODER is
begin
Out(0) <= Enable or (not A nand not B);
Out(1) <= Enable or (A nand not B);
Out(2) <= Enable or (not A nand B);
Out(3) <= Enable or (A nand B);
end ARC.DECODER;
2nd - 2:4 decoder using "select" and "with" (case) :
entity DECODER is
port ( SEL : in std_logic_vector(1 downto 0);
outlet : out std_logic_vector(3 downto 0)
);
end DECODER;
architecture ARC.DECODER of DECODER is
begin
with SEL select
outlet <= "0001" when "00",
"0010" when "01",
"0100" when "10",
"1000" when "11",
"0000" when others;
end ARC.DECODER;
3rd - 2:4 decoder using "signal", "component" and "map" :
entity DECODER is
Port (A,B : in STD_LOGIC ;
F0,F1,F2,F3 : out STD_LOGIC );
end entity DECODER;
architecture ARC.DECODER of DECODER is
signal A_sig, B_sig : STD_LOGIC;
component INV
port (In1 : in STD_LOGIC ;
Out1 : out STD_LOGIC );
end component;
component AND_2
port (In1, In2 : in STD_LOGIC ;
Out1 : out STD_LOGIC );
end component;
begin
U1 : INV port map (A, A_sig);
U2 : INV port map (B, B_sig);
U3 : AND2 port map (A_sig, B_sig, F0);
U4 : AND2 port map (A, B_sig, F1);
U5 : AND2 port map (A_sig, B, F2);
U6 : AND2 port map (A, B, F3);
end architecture ARC.DECODER;
How does the avr automatically maintain a constant voltage level in a generator?
The AVR (automatic voltage regulator) measures the generator voltage output and varies the field voltage (which varies the strength of the rotating magnetic field) to maintain a fixed output voltage.
Some generators excite (power) the AVR and field windings from the main stator, some provide a separate stator winding just for field excitation, and others provide a separate stator winding and rotating permanent magnets (called PMG) for field excitation.
The generators that do not have permanent magnets rely on residual magnetism for the initial voltage to start the system or may provide initial voltage from the engine's starting battery.
What the function of input rectifier at the digital multimeter?
The indicater meter is a DC device, so the rectifier changes AC to DC.
A meter could not respond to AC.
Name the charge responsible for current flow?
it is electron because there are free electrons in a conductor .The atoms are fixed on their places.The positive ion (as a result of emission of an electron which is negatively charged ) remains still on its place and hence the free electrons are responsible for the current flow . In solutions and gases the positive ions can also move because they are free to move unlike in the metal
What is the modulation of frequency?
It is a device or electronic circuit that changes the frequency of an oscillator according to the amplitude of modulating signal. For instance, if the modulation is linear, the modulator changes the frequency proportional to the amplitude of the modulating voltage.
Is a voltmeter placed parallel to a circuit?
Depends. What did you want to measure? If it's voltage drop across the incandescent element, then you had better hook up your infinite resistance voltmeter in parallel with the lamp.
How do transistors amplify weak signal?
A transistor controls the flow of current between the emitter and collector.
The larger current is supplied by the power supply, across the emitter and collector.
The flow is then controlled by a small current applied to the base connection.
So, a large current flow mimics the small signal current.
Limits are reached, when the transistor gets close to being fully switched on or off. This will cause distortion. To avoid this, more amplification is provided by a series of transistor amplifiers, one after the other.
Avoiding Bias in Assessment Tasks and Procedures?
It is important that educators do not show bias on assessments. The teachers must be knowledgeable about the culture of their students so that they do not offend students with certain test questions.
Latest technology in electronics and communication?
latest technology in communication slide should be 4G and 6th sense technology.
Design a mod-7 synchronous counter using JK Flip-Flops?
You do it by studying, and doing your homework by yourself instead of trying to get someone else to do it for you.
Is current equals voltage divided by resistance series circuits parallel circuits or both?
Ohm's law: Current equals voltage divided by resistance.
It does not matter if the circuit is series or parallel or both. Ohm's law still applies. What you do need to consider is that it applies for each component on its own merits. The is one of the fundamentals of circuit analysis, the progressive analysis of each component, taking account of what you know for that component, until you know everything about all components.
How many 125 watt bulbs can be used on a 15amp circuit?
Assuming that your voltage is 120 volts the maximum wattage on that circuit is W = A x V = 15 x 120 = 1800 watts. Code only allows circuits to be loaded up to 80% capacity. 1800 x .8 = 1440. 1440/25 = 57 lamps.
Assuming that your voltage is 240 volts the maximum wattage on that circuit is W = A x V = 15 x 240 = 3600 watts. If the question is from a 240 volt country you will have to find out what the local electrical regulations are for circuit loading.
What should the beat frequency of two in-tune instruments be?
The beat frequency of two in-tune musical instruments is zero.
How do touch screen phones work?
To allow people to use touch commands that require multiple fingers, the iPhone uses a new arrangement of existing technology. Its touch-sensitive screen includes a layer ofcapacitive material, just like many other touch-screens. However, the iPhone's capacitors are arranged according to a coordinate system. Its circuitry can sense changes at each point along the grid. In other words, every point on the grid generates its own signal when touched and relays that signal to the iPhone's processor. This allows the phone to determine the location and movement of simultaneous touches in multiple locations. Because of its reliance on this capacitive material, the iPhone works only if you touch it with your fingertip -- it won't work if you use a stylus or wear non-conductive gloves.
The iPhone's screen detects touch through one of two methods: Mutual capacitance or self capacitance. In mutual capacitance, the capacitive circuitry requires two distinct layers of material. One houses driving lines, which carry current, and other houses sensing lines, which detect the current at nodes. Self capacitance uses one layer of individual electrodes connected with capacitance-sensing circuitry.A mutual capacitance touch-screen contains a grid of sensing lines and driving lines to determine where the user is touching.
A self capacitance screen contains sensing circuits
and electrodes to determine where a user is touching.
Both of these possible setups send touch data as electrical impulses. In the next section, we'll take a look at exactly what happens.
The iPhone's processor and software are central to correctly interpreting input from the touch-screen. The capacitive material sends raw touch-location data to the iPhone's processor. The processor uses software located in the iPhone's memory to interpret the raw data as commands and gestures. Here's what happens:
- Signals travel from the touch screen to the processor as electrical impulses.
- The processor uses software to analyze the data and determine the features of each touch. This includes size, shape and location of the affected area on the screen. If necessary, the processor arranges touches with similar features into groups. If you move your finger, the processor calculates the difference between the starting point and ending point of your touch.
- The processor uses its gesture-interpretation software to determine which gesture you made. It combines your physical movement with information about which application you were using and what the application was doing when you touched the screen.
- The processor relays your instructions to the program in use. If necessary, it also sends commands to the iPhone's screen and other hardware. If the raw data doesn't match any applicable gestures or commands, the iPhone disregards it as an extraneous touch.
All these steps happen in an instant -- you see changes in the screen based on your input almost instantly. This process allows you to access and use all of the iPhone's applications with your fingers.
The shape of the screen changes when you need it to as well -- you can shift the perspective from vertical to horizontal by tilting the phone. An accelerometer inside the iPhone lets the operating system know to change the orientation of the image on the screen. This means that you can scroll through long lists of music files on a long, narrow screen, and you can watch movies in a widescreen format. You can learn more about accelerometers in How the Nike + iPod Works and How the Wii Works.
What color is hotwire in a typical 12 volt circuit?
Normally it is Red but not 100% of the time. Always check with a multimeter.
Why do electrical appliance work on ac current an not in dc?
Mainly because your home is supplied with a.c. not d.c. Even those appliances (audio systems, etc.) that require d.c. supplies can be connected to an a.c. supply, because they have internal transformers/rectifiers which change the a.c. voltage to the required d.c. voltage.
