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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
How much power does a 300 VA UPS consume?
From the description given its output power would be 300 Volt-Amps which is almost the same as 300 Watts but may not be, depending on the power factor.
If we allow, say, 10% extra for power losses, the UPS (Un-interruptable Power Supply to those who don't know what such things are) may consume about 330 Watts from your building's main electrical power supply.
If you need to have a more accurate idea of the power it takes why not look at the rating plate on the UPS unit itself? Or if you had a Wattmeter you could measure the maximum power drawn when it is working at full load charging its batteries.
Voltage gain is the ratio of the output voltage of an amplifier to its input voltage.
Why resistors are connected in series with the voltage source and in parallel with current source?
a voltage source has very less(negligible)resistance.thus is considered as a short.if connected in parallel to a resistor will draw all the current acting as a short.thus is always connected in series of a resistor.where as a current source has tremendous resistance(infinity).thus if connected in series will be conidered as an open branch and no current will flow through it other than the source current.
Since they are in series you can use R=R1+R2+R3... for Total Resistance, then use Ohms Law of I=V/R and solve for I and R. (remember that V and I are also Totals, unless you brake them down at each point)
Applications of wien bridge oscillator?
A Wein Bridge Oscillator is a oscillator which is used for the measurement of Audio Frequency.
On what factors capacitance of a capacitor depends on?
The job of a capacitor is to store charge onto its plates. The amount of electrical charge that a capacitor can store on its plates is known as its Capacitance value and depends upon three main factors.
- The surface area, A of the two conductive plates which make up the capacitor, the larger the area the greater the capacitance.
- The distance, d between the two plates, the smaller the distance the greater the capacitance.
- The type of material which separates the two plates called the "dielectric", the higher the permittivity of the dielectric the greater the capacitance.
- Bit justification is needed in PDH - No would standards available at optical interface in PDH - line rates are not standard - Interfacing problem at multivendor equipment - PDH supports 16E1s and SDH supports 63E1s
A stimulant containing dextro-amphetamines to treat ADHD or narcolepsy.
Please tell the website where you get bst information about satellite and satellite communiction?
Google!
What does No-load voltage mean?
A no load voltage means the power level that is giving from the output pins power converter. This is when 0% load is given.
What are the functions of the resistor?
Resistance: Electrical resistance describes how an electrical conductor (a wire) opposes the flow of an electrical current (flow of electrons). To overcome this opposition a voltage (a energy) must dropped (used) across the conductor (wire). Resistance can be described by ohms law: Ohms Law: R = V / I (Resistance = Voltage / Current) (resistance measured in ohms) where: Voltage [V]= the energy lost across an component (voltage measured in volts). Current [I] = the charge (electrons) flowing through an component (current measured in Amps). Electrical resistance can be thought of as sticking your hand out a car window. The faster [current] you drive the harder the wind presses [resistance] against you hand and therefore it takes more energy [voltage] to hold your hand steady. When trying to overcome electrical resistance, the electrical energy lost is turned into heat. This is how the elements of a household stove, toaster, and fan heater work. Because of the vacuum in a light bulb, the electrical energy lost is instead turned into light. It can be seen the electrical resistance plays a large role in modern life. Resistor: The resistor is the most common electronic component and is used to limit and/or control the voltage and current in an electronic circuit. Resistors are carefully manufactured to provide a predetermined value of electrical resistance which may range from 0.1 ohms to 100,000,000 ohms, depending on the application. The physical size of a resistor also varies dependant on the amount of power passing through the resistor, given by: P = V x I (Power = Voltage x Current) (power measured in watts) There are also many types of resistors including: · Variable Resistor - changes resistance when its shaft is rotated (volume knob on a stereo). · Thermistor - changes resistance when the temperature changes (used in a thermostat). · Light Dependant Resistor (LDR) - changes resistance when the lighting changes (used in children's night-lights). Resistor Example: An LED is a small red light (such as the one on the front of most TVs) and requires 2.0 volts and 0.02 amps to operate correctly. If we connected that LED up directly to a 12 volt battery, the voltage would be too high, and too much current would flow… the LED would blow up. We need to use a resistor to limit the voltage and current. But which value of resistance should the have resistor? Uses ohms law: R = V / I = (12.0 - 2.0) / 0.02 = 500 ohms (Note: the voltage across the resistor is the battery voltage minus the voltage we want across the LED) But which value of power should the resistor be capable of handling? P = V x I = (12.0 - 2.0) / 0.02 = 0.2 Watts
What is common mode rejection ratio Explain briefly?
common mode rejection ratio is defined as ratio of differential voltage gain to common mode voltage gain
Common mode rejection ratio is the ability of the circuit to reject common entries like noise.
The only way is to contact the manufacturer or supplier with the model number at hand, normally it is the large number that is on the ID plate
The only way is to contact the manufacturer or supplier with the model number at hand, normally it is the large number that is on the ID plate
If a Self excited machine fails to excite what is the reason?
A break in the shunt circuit which is provided with excitation voltage from the armature circuit.
Excessively worn armature brushes.
This device must be started without any load attached.
Advantages and disadvantages of an ionization smoke detectors?
Cheap and effective when maintained properly.
Smoke detectors will run out of battery over time as they are not wired in to the houses electrical system.
Statistics show that far fewer people die in house fires when smoke alarms are present.
When the smoke alarms are placed to close to bathrooms steam may interfere with the detector, triggering false alarms.
Ionization detectors seem to respond better with high flames which could be a problem under certain circumstances.
What Is The Function of A L.E.D?
LED or light-emitting diode refers to a semiconductor material that emits light when electricity passes through it. It is used for visual signals, illumination and data communication.
This is an abbreviation for gigabaud; a giga prefix is equivalent to one thousand million and baud is measure using in information theory and datacomms and indicates symbols per second. So 1 gigabaud is one thousand million symbols per second.
Difference between class A classBclassABclassC amplifier?
Difference is in the work spot of voltage. Because of that, difference is in the graphics too. Also, angle(A)>180 , 90<angle(B)<180, angle(C)<90
Applications of cathode ray oscilloscope?
laboratory experiments
Electricians use them to view signal voltages, usually as a two-dimensional graph of one or more electrical potential differences (vertical axis) plotted as a function of time or of some other voltage (horizontal axis).
Oscilloscopes are used in the sciences, medicine, engineering, telecommunications, and industry.
Special-purpose oscilloscopes may be used for such purposes as analyzing an automotive ignition system, or to display the waveform of the heartbeat.
Fullwave center-tap rectifier theory?
The Center-Tapped Full-Wave Rectifier
A center-tapped rectifier is a type of full-wave rectifier that uses two diodes connected to the secondary of a center-tapped transformer, as shown in Figure (a). The input voltage is coupled through the transformer to the center-tapped secondary. Half of the total secondary voltage appears between the center tap and each end of the secondary winding as shown.
Read more: http://www.daenotes.com/electronics/devices-circuits/center-tapped-full-wave-rectifier#ixzz2IVoFQ5erFor a positive half-cycle of the input voltage, the polarities of the secondary voltages are as shown in Figure (a). This condition forward-biases diode D1 and reverse-biases diode D2. The current path is through D1 and the load resistor RL, as indicated. For a negative half-cycle of the input voltage, the voltage polarities on the secondary are as shown in Figure (b). This condition reverse-biases D1 and forward-biases D2. The current path is through D2 and RL, as indicated. Because the output current during both the positive and negative portions of the input cycle is in the same direction through the load, the output voltage developed across the load resistor is a full-wave rectified dc voltage, as shown.
Read more: http://www.daenotes.com/electronics/devices-circuits/center-tapped-full-wave-rectifier#ixzz2IVoev4Vf
How is the capacitor able to account for AC Ripples?
Ripple Voltage is voltage variation across the load and it is the AC component. To answer this question, consider a Half Wave rectifier with a smoothing capacitor: This rectifier will consist of a sinusoidal voltage source, an ideal diode, a capacitor in parallel with the load. At t=0, the voltage across capacitor = load voltage When the circuit is switched on, the capacitor is fully charged as the sinusoidal source reaches its peak. However, the sinusoidal nature causes the source voltage to decline after reaching the peak. This means that no current will flow through the diode. But the capacitor is still charged. So this will supply current to the load while it discharges. But during the discharging period (till the sinusoidal picks up again), the load voltage is an exponential function = peak voltage *exp-[(t - t')*resistance of load*capacitance] Now a key point is that the pulsating current is flowing through the diode to recharge the capacitor. Because of this constant charge and discharge of the capacitor in the cycle, the load voltage has AC ripples. At the same time load current is never zero and is directly prop to load voltage. The dc component >> ac component and the ripple voltage is greatly reduced by the capacitance esp a large one. You can minimize these by choosing a large capacitance. This is how a capacitor accounts for AC ripples. You can never actually rid these ripples even if you use a full-wave rectifier! Google search half - wave rectifier graphs on the ripples to understand this!! --- Sona
