answersLogoWhite

0

What else can I help you with?

Continue Learning about Electrical Engineering

Why do the reading differ for increasing and decreasing values of the lamp voltages?

at the time of decreasing lamp voltage as the temperature is already high the gas in the lamp is already in ionized state leading to different resistance ,but when increasing voltage the gas is not in ionized state it ready to ionize ,so there is slightly variation in resistance . :)


Is a device that changes the voltage of an alternating current with little loss of energy?

The device you are referring to is called a transformer. Not only can a transformer increase voltage, it can decrease voltage as well. These are known as a step up transformer for increasing voltages and step down for decreasing voltages.


What is nonlinear resistance?

A nonlinear resistance is a resistance which is different for different voltages ie current is not proportional to voltage. An example of this is the filament of an incandescent lamp.


What are the voltages in secondary transmission electric lines?

A: Those voltages are called distribution voltages to differentiate from transmission voltages. And that varies from state to state and locals . Usually around 10kv to 20 kv


Why does the no-load characteristic differ for increasing and decreasing excitation current?

The no-load characteristic of a generator differs for increasing and decreasing excitation current due to magnetic hysteresis, residual magnetism, and core saturation effects. When the excitation current increases, the magnetic domains in the iron core gradually align with the applied magnetic field, resulting in a higher generated electromotive force (EMF). However, as the excitation current decreases, these magnetic domains do not immediately return to their original unaligned state. This lag in realignment causes the generated voltage to remain higher during the decreasing phase of excitation than during the increasing phase at the same level of excitation current. This phenomenon is known as magnetic hysteresis. Even when the excitation current is zero, the magnetic core retains some level of magnetisation, known as residual magnetism. This residual magnetic field means that when the excitation current starts increasing again, it takes additional current to overcome this residual alignment before the generated voltage rises significantly. As a result, the voltage is initially lower when increasing the excitation current from zero. Conversely, during the decreasing phase, the residual magnetism keeps the voltage higher than it would be if the core were fully demagnetised, further contributing to the difference between the increasing and decreasing curves. As the excitation current increases, the magnetic core of the generator approaches saturation. Near saturation, any further increase in excitation current results in only a small increase in generated voltage because the core's magnetic domains are almost fully aligned. When the excitation current decreases from this saturated state, the magnetic domains gradually return to a less aligned state. This gradual realignment causes the generated voltage to decrease differently than it increased, contributing to the asymmetry between the increasing and decreasing excitation phases.

Related Questions

If the excitation of generator changes what happens to the terminal voltage?

By Decreasing the excitation voltage the terminal voltage will decrease and similarly by increasing the excitation voltages the terminal voltage will also increases.


Are the terms voltage limiter and voltage regulator interchangeable?

No. A voltage regulator usually can provide control in both directions (increasing or decreasing voltages). A voltage limiter clamps the voltage to below a specific level.


Why do the reading differ for increasing and decreasing values of the lamp voltages?

at the time of decreasing lamp voltage as the temperature is already high the gas in the lamp is already in ionized state leading to different resistance ,but when increasing voltage the gas is not in ionized state it ready to ionize ,so there is slightly variation in resistance . :)


Is a device that changes the voltage of an alternating current with little loss of energy?

The device you are referring to is called a transformer. Not only can a transformer increase voltage, it can decrease voltage as well. These are known as a step up transformer for increasing voltages and step down for decreasing voltages.


What are the factors that influence the speed of the direct-current shunt motor with increasing load?

.The magnitude of the voltage and current of both the armature and shunt field coil. To decrease the speed when the load is increasing then increase the shunt field current while decreasing the armature voltage or current. To increase the speed while the load is increasing then increase the armature current while decreasing the shunt field current. The decreasing and increasing of these currents and voltages can be done by connecting a variable resistor in series or parallel with each of the armature and/or shunt field coil.


What is nonlinear resistance?

A nonlinear resistance is a resistance which is different for different voltages ie current is not proportional to voltage. An example of this is the filament of an incandescent lamp.


What is the maximum voltage of incandescent light bulbs?

The maximum voltage of incandescent light bulbs is up to about three hundred volts. They can also go down as low as 1.5 volts. Incandescent light bulbs are the least efficient lighting system. More modern methods like flourescent lightbulbs are far more efficient.


What is the significance of negative values of voltages and currents?

Direction only. If you reverse the connections to your voltmeter or ammeter you get the same size readings but the directions are indicated to be the opposite way around, by reversal of sign.


Can incandescent lamps be 277V?

High Intensity Discharge fixtures can use 277 input voltages. These types of fixtures have ballasts and different wattage lamps available. The fixtures are mostly used in industrial and commercial applications.


What are the voltages in secondary transmission electric lines?

A: Those voltages are called distribution voltages to differentiate from transmission voltages. And that varies from state to state and locals . Usually around 10kv to 20 kv


How one can increase the penetrating power of x-rays?

X-rays can be given increased power to penetrate by increasing their frequency (shortening their wavelength). This is generally accomplished by increasing the operating voltage of the X-ray tube. Higher voltages will accelerate electrons more, and their increased energy will result in more energetic ("harder") X-rays at the target of the anode.


Why the graph of breakdown voltage is cheaper than knee voltage?

Break down voltages happens at low voltages (.6 for silicon & .3 for germanium), whereas knee voltages at higher voltages. That's why its cheaper.