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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
Block Diagram of Microprocessor based system?
A computer can process data, pictures, sound and graphics. They can solve highly complicated problems quickly and accurately.
Input Unit:
Computers need to receive data and instruction in order to solve any problem. Therefore we need to input the data and instructions into the computers. The input unit consists of one or more input devices. Keyboard is the one of the most commonly used input device. Other commonly used input devices are the mouse, floppy disk drive, magnetic tape, etc. All the input devices perform the following functions.
- Accept the data and instructions from the outside world.
- Convert it to a form that the computer can understand.
- Supply the converted data to the computer system for further processing.
Storage Unit:
The storage unit of the computer holds data and instructions that are entered through the input unit, before they are processed. It preserves the intermediate and final results before these are sent to the output devices. It also saves the data for the later use. The various storage devices of a computer system are divided into two categories.
1. Primary Storage: Stores and provides very fast. This memory is generally used to hold the program being currently executed in the computer, the data being received from the input unit, the intermediate and final results of the program. The primary memory is temporary in nature. The data is lost, when the computer is switched off. In order to store the data permanently, the data has to be transferred to the secondary memory.
The cost of the primary storage is more compared to the secondary storage. Therefore most computers have limited primary storage capacity.
2. Secondary Storage: Secondary storage is used like an archive. It stores several programs, documents, data bases etc. The programs that you run on the computer are first transferred to the primary memory before it is actually run. Whenever the results are saved, again they get stored in the secondary memory. The secondary memory is slower and cheaper than the primary memory. Some of the commonly used secondary memory devices are Hard disk, CD, etc.,
Memory Size:
All digital computers use the binary system, i.e. 0's and 1's. Each character or a number is represented by an 8 bit code.
The set of 8 bits is called a byte.
A character occupies 1 byte space.
A numeric occupies 2 byte space.
Byte is the space occupied in the memory.
The size of the primary storage is specified in KB (Kilobytes) or MB (Megabyte). One KB is equal to 1024 bytes and one MB is equal to 1000KB. The size of the primary storage in a typical PC usually starts at 16MB. PCs having 32 MB, 48MB, 128 MB, 256MB memory are quite common.
Output Unit:
The output unit of a computer provides the information and results of a computation to outside world. Printers, Visual Display Unit (VDU) are the commonly used output devices. Other commonly used output devices are floppy disk drive, hard disk drive, and magnetic tape drive.
Arithmetic Logical Unit:
All calculations are performed in the Arithmetic Logic Unit (ALU) of the computer. It also does comparison and takes decision. The ALU can perform basic operations such as addition, subtraction, multiplication, division, etc and does logic operations viz, >, <, =, 'etc. Whenever calculations are required, the control unit transfers the data from storage unit to ALU once the computations are done, the results are transferred to the storage unit by the control unit and then it is send to the output unit for displaying results.
Control Unit:
It controls all other units in the computer. The control unit instructs the input unit, where to store the data after receiving it from the user. It controls the flow of data and instructions from the storage unit to ALU. It also controls the flow of results from the ALU to the storage unit. The control unit is generally referred as the central nervous system of the computer that control and synchronizes its working.
Central Processing Unit:
The control unit and ALU of the computer are together known as the Central Processing Unit (CPU). The CPU is like brain performs the following functions:
• It performs all calculations.
• It takes all decisions.
• It controls all units of the computer.
A PC may have CPU-IC such as Intel 8088, 80286, 80386, 80486, Celeron, Pentium, Pentium Pro, Pentium II, Pentium III, Pentium IV, Dual Core, and AMD etc.
Why do you connect a capacitor to an AC motor?
To induce a phase shift between the rotor and stator (stationary winding).
AC motors are not good at starting up, they need 'help' to get started/they need two magnetic fields to push against each other to generate torque. This capacitor is called a 'starting' capacitor and provides an extra 'boost' to get the motor turning by increasing the phase angle between the rotor and stator winding. Once the motor is at it's proper operating speed, the capacitor must be disconnected or it will burn up.
There are also motor designs that use a run capacitor. This capacitor usually has a smaller capacitance than a start capacitor (so it provides a smaller phase shift), but is designed for continuous operation. These motors don't provide as much starting torque as a similar motor with a start capacitor. Other motors will have both a start and run capacitor. The start capacitor provides significant phase shift between the rotor and stator, and thus significant torque. Once the motor is at speed, the start capacitor is switched out of the circuit, and the run capacitor is left in the circuit to provide a smaller phase shift.
What effect does reducing resistance have on the power in a circuit?
Since power = voltage2/resistance, reducing the resistance will increase the power of the circuit. Incidentally, power is not 'consumed'; it's energy that's consumed.
A trimmer capacitor is a semi-adjustable capacitor placed across a variable tuning capacitor and pre-set to allow the main capacitor to track correctly with another variable capacitor on the same shaft. The adjustment takes out any differences introduced by the connected circuit.
What to do if the voltage is to high in your house?
It is very difficult to have residential voltage that is too high. Utility companies go to great lengths to keep voltages and frequency within very close tolerances. In the US residential voltage for lighting and outlets is a nominal 115 Volts, and normally doesn't vary more than 3 to 5 volts. That won't hurt anything. The other voltage present in residential buildings is 220 Volts. That voltage is used almost exclusively for electric dryers, water heaters, and electric ranges. It is used to provide large amounts of power and still keep the size of the electrical conductor reasonable. If you had to use 115 Volts you would draw twice the amps requiring a conductor capable of twice the capacity of a conductor destined for 115 Volt use. Those are more expensive and much harder to work with. DO NOT MIX THE TWO VOLTAGES! Plugging a 115 volt device in a 220 volt circuit will probably destroy the device. Plugging a 220 volt device in a 115 volt circuit will destroy the wiring if not properly protected, and may cause a fire. All wiring used in a residential setting is rated at 600 Volts. That means that the insulation will withstand 600 volts without breaking down. Therefore you can use the wire for any application in the house PROVIDED is is the proper size for the expected current. Fixtures (Switches, Outlets etc.) are rated by voltage and current. The rating is right on the device. You may have noticed that outlets have different blade patterns. That is to prevent plugging the wrong thing in an outlet. Since appliances are rated by voltage and current (amps), or voltage and power (watts) do not plug appliances in the wrong voltage or current. The appliance manufacturer has installed the proper plug for his appliance. You must use the properly configured outlet. Building inspectors insure that the residential circuits have the correct pattern devices on each circuit. If you must replace a device make sure that the black wire goes to the gold connector, silver goes to silver connector, and green goes to green. If you are really uncomfortable with your home wiring, hire a licensed electrician to verify that everything is correct. After that you can replace any device as long as you turn the device off first and then make sure you install the new device EXACTLY as the old one was installed.
Which 12 volt bulb will draw the most current when connected to a 12 volt battery?
The bulb with the lowest resistance.
Current = Volts / Resistance
How a Oscillator works without giving any input signal?
just like the simple oscillator that v c in our normal life which is a Pendulum.
in pendulum there is the difference between the potential energy and then the theory of inertia is applied similarly it happens with the case in the electronics whr the +Vcc voltage is there and its difference with the ground helps in oscillation using the tank circuit.
shri krishan sharma
How do resistors act in series?
In brief, the overall or net resistance changes and the resistors in series and/or parallel can be represented by a single equivalent resistor.
If you consider series resistors the equivalent resistance of the series would be:
R = R1+R2+ ... +Rx
The equivalent resistance of parallel resistors would be:
1/R = 1/R1 + 1/R2 + ... + 1/Rx
One rule to always remember when dealing with series and parallel resistors is the voltage across each resistor in parallel will be the same as defined in Kirchhoff Voltage Law and the current across each resistor in series will be the same by Kirchhoff Current Law.
More information can be found at this web site.
http://physics.bu.edu/py106/notes/Circuits.html
What do you need to build your own dynamo?
Physics is reversible. SO you can use the inverse properties of any DC motor. Which means that when you give electricity, the motor rotates. But if you rotate the motor, with some extra circuit, It can act like a dynamo.
State ohms law and give the formula?
The Ohm's law is defined as voltage propositional to current. The equation given by
V=IR
R IS THE PROPOSITIONAL CONSTANT
What is the Disadvantages of semiconductor to other materials?
what is a semiconductor able to do that other materials cabbot
Is the output power more than input power in a transformer?
No. By "energy", you must mean "power"?
Energy = power * time.
Anyway,
No transformer can step up energy. Even in a perfect transformer, you would only receive the energy output equal to the energy input.
There is always some loss of energy due to resistance of the windings and unwanted electrical currents induced in the core. Both convert some of the energy input into heat.
Pulmonary circulation is when the right ventricle contracts sending blood through the pulmonary artery to the lungs to get oxygenated, then back through the pulmonary vein into the left atrium.
What medium guarantees immunity from emi and rfi interference?
Fox news, cause it is fair and balanced.
100 Base-FX 1000 Base LX
If if you think of the sound of music, the amplitude tells how loud it is and the frequency tells how high the sound is.
Amplitude is the measure of a magnitude of oscillation of a wave .
Frequency is the measure of number of times that a repeated event occurs per unit time.
f = 1/T
f = frequency
T = time period
Is an ammeter a device specially designed to measure current?
An ammeter is a measuring instrument used to measure the electric current in a circuit.
Why does the output frequency of a full wave rectifier double that of input frequency?
One cycle of the AC input consists of a positive half-cycle followed be a negative half cycle. The FW rectifier basically reverses the polarity of one of the half-cycles, so there are now two positive pulses per single input cycle, effectively doubling the frequency.
Of course the rectifier may be wired for the opposite polarity, with two negative pulses per input cycle, but the same principle applies.
How do you choose q point on load line?
the fixed amount of current and voltages are developed across the transistor is called biasing. thus the fixed voltages and current developed are called Q-point
When charge are able to flow directly from the circuit into Earth a ciruit electrically?
That is what the Earth wire does. Normally it does not carry current but it has this important safety function.
What materials are conductors in a torch?
The conducting path of a torch is a simple circuit: Battery to switch, switch to bulb, bulb back to battery. Provided the switch is on, and there are no breaks in the circuit wiring (and the bulb is good), the torch should work.
What is the common transistor configuration used for signal amplifier?
Class A amplifiers for signals and class AB for power output. The bias is often set up as a self biased amp.
What does fob in key fob stand for?
Fob stands for Fresh Of The Boat. FOB is a term for a new person in the country that stands out
