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Electrostatics
Electrostatics is the branch of physics that deals with the study of charges at rest. A common electrostatic phenomena is plastic wrap sticking to your hand and itself when removed from the box. Everything to do with electrostatics goes in this category.
1,860 Questions
How do you shock someone with static electricity?
To shock someone with static electricity, build up as much charge as possible by shuffling your feet on a carpet or rubbing a balloon on your hair. Then, touch the person with your charged body to transfer the electric shock.
What is the function of electroscope?
An electroscope is used to detect the presence of electric charge, either positive or negative. It works by using the principle of electrostatic induction to indicate the presence of charge on an object through the divergence of a pair of thin metal leaves that are suspended in the apparatus.
Construction of a tunnel diode?
Tunnel Diode Devices: The TUNNEL DIODE is a pn junction with a very high concentration of impurities in both the p and n regions. The high concentration of impurities causes it to exhibit the properties of a negative-resistance element over part of its range of operation, as shown in the characteristic curve in figure 2-39. In other words, the resistance to current flow through the tunnel diode increases as the applied voltage increases over a portion of its region of operation. Outside the negative-resistance region, the tunnel diode functions essentially the same as a normal diode. However, the very high impurity density causes a junction depletion region so narrow that both holes and electrons can transfer across the pn junction by a quantum mechanical action called TUNNELING. Tunneling causes the negative-resistance action and is so fast that no transit-time effects occur even at microwave frequencies. The lack of a transit-time effect permits the use of tunnel diodes in a wide variety of microwave circuits, such as amplifiers, oscillators, and switching devices. Fig. 6 Tunnel-diode characteristic curve Tunnel Diode Frequency Converters and Mixers: Tunnel diodes make excellent mixers and frequency converters because their current-voltage characteristics are highly nonlinear. While other types of frequency converters usually have a conversion power loss, tunnel-diode converters can actually have a conversion power gain. A single tunnel diode can also be designed to act as both the nonlinear element in a converter and as the negative-resistance element in a local oscillator at the same time. Practical tunnel-diode frequency converters usually have either a unity conversion gain or a small conversion loss. Conversion gains as high as 20 dB are possible if the tunnel diode is biased near or into the negative-resistance region. Although high gain is useful in some applications, it presents problems in stability. For example, the greatly increased sensitivity to variations in input impedance can cause high- gain converters to be unstable unless they are protected by isolation circuitry. As with tunnel-diode amplifiers, low-noise generation is one of the more attractive characteristics of tunnel-diode frequency converters. Low-noise generation is a primary concern in the design of today's extremely sensitive communications and radar receivers. This is one reason tunnel-diode circuits are finding increasingly wide application in these fields. Fig. Tunnel-diode oscillator. A tunnel diode, biased at the center point of the negative- resistance range (point B in figure 2-39) and coupled to a tuned circuit or cavity, produces a very stable oscillator. The oscillation frequency is the same as the tuned circuit or cavity frequency. Microwave tunnel-diode oscillators are useful in applications that require microwatts or, at most, a few milliwatts of power, such as local oscillators for microwave superheterodyne receivers. Tunnel-diode oscillators can be mechanically or electronically tuned over frequency ranges of about one octave and have a top-end frequency limit of approximately 10 gigahertz. Tunnel-diode oscillators that are designed to operate at microwave frequencies generally use some form of transmission line as a tuned circuit. Suitable tuned circuits can be built from coaxial lines, transmission lines, and waveguides. An example of a highly stable tunnel-diode oscillator is shown in figure 2-40. A tunnel-diode is loosely coupled to a high-Q tunable cavity. Loose coupling is achieved by using a short, antenna feed probe placed off-center in the cavity. Loose coupling is used to increase the stability of the oscillations and the output power over a wider bandwidth. The output power produced is in the range of a few hundred microwatts, sufficient for many microwave applications. The frequency at which the oscillator operates is determined by the physical positioning of the tuner screw in the cavity. Changing the output frequency by this method is called MECHANICAL TUNING. In addition to mechanical tuning, tunnel-diode oscillators may be tuned electronically. One method is called BIAS TUNING and involves nothing more than changing the bias voltage to change the bias point on the characteristic curve of the tunnel-diode. Another method is called VARACTOR TUNING and requires the addition of a varactor to the basic circuit. Varactors were discussed in NEETS, Module 7, Introduction to Solid-State Devices, and Power Supplies, Chapter 3. Tuning is achieved by changing the voltage applied across the varactor which alters the capacitance of the tuned circuit. Fig. 5 Tunnel-diode amplifier Tunnel Diode Amplifiers: Low-noise, tunnel-diode amplifiers represent an important microwave application of tunnel diodes. Tunnel-diode amplifiers with frequencies up to 85 gigahertz have been built in waveguides, coaxial lines, and transmission lines. The low-noise generation, gain ratios of up to 30 dB, high reliability, and light weight make these amplifiers ideal for use as the first stage of amplification in communications and radar receivers. Most microwave tunnel-diode amplifiers are REFLECTION-TYPE, CIRCULATOR-COUPLED AMPLIFIERS. As in oscillators, the tunnel diode is biased to the center point of its negative-resistance region, but a CIRCULATOR replaces the tuned cavity. A circulator is a waveguide device that allows energy to travel in one direction only, as shown in figure 2-41. The tunnel diode in figure 2-41 is connected across a tuned-input circuit. This arrangement normally produces feedback that causes oscillations if the feedback is allowed to reflect back to the tuned- input circuit. The feedback is prevented because the circulator carries all excess energy to the absorptive load (R L). In this configuration the tunnel diode cannot oscillate, but will amplify. The desired frequency input signal is fed to port 1 of the circulator through a bandpass filter. The filter serves a dual purpose as a bandwidth selector and an impedance-matching device that improves the gain of the amplifiers. The input energy enters port 2 of the circulator and is amplified by the tunnel diode. The amplified energy is fed from port 2 to port 3 and on to the mixer. If any energy is reflected from port 3, it is passed to port 4, where it is absorbed by the matched load resistance. Q-48. Name the procedure used to reduce excessive arcing in a magnetron? Q-49. What causes the negative-resistance property of tunnel diodes? Q-50. What determines the frequency of a tunnel-diode oscillator? Q-51. Why is the tunnel diode loosely coupled to the cavity in a tunnel-diode oscillator? Q-52. What is the purpose of the circulator in a tunnel-diode amplifier?
Electrostatic energy is the potential energy stored in an object due to its electric charge. It is created by the interaction of charged particles in the presence of an electric field. This energy can either attract or repel charged particles based on their polarity.
I don't know how to convert it, but I'll answer the second question.
Mechanical energy is made from say...a Bike, the energy that makes it move and pulls it forward is considered mechanical energy. Electrical energy is made from a lightbulb, or anything that is electrical. So to answer that question..No, mechanical energy is not the same as electrical energy.
Answer:Electrical Energy is consumed by, it is not made from a lightbulb or anything that is electrical...Steam (thermal energy) drives a turbine which drives a generator (mechanical energy) which produces electrical energy.
No they are not the same thing aside from both being forms of energy.
Electrical energy can be converted into mechanical energy such as plugging in your blender or vacuum cleaner and mechanical energy can be converted to electrical energy as mentioned in the example of the generator above.
Static electricity is defined as?
- Static electricity is an imbalance of electric charges within or on the surface of a material.
- The charge remains until it is able to move away by means of an electric current or electrical discharge.
- Static electricity is named in contrast with current electricity, which flows through wires or other conductors and transmits energy
What are some 'good' and 'bad' static electricity?
Good static electricity: Used in electronics to remove dust from surfaces or in printing to make sure ink adheres properly.
Bad static electricity: Causes annoying shocks, damage to electronic devices, and can be a fire hazard in certain environments like gas stations.
Water is a covalent molecule (one where the electrons are shared between the atoms). If you ever tried to share something with someone, then you know that it is difficult to share equally. The same is true for atoms. Some atoms like to hog electrons more than others (measured by what is called electronegativity), so they will pull the electrons towards themselves and away from the other atoms.
In water, oxygen is the electron hog (has a higher electonegativity) and the hydrogen is left wanting. The electrons spend more time with the oxygen atom, so it gains a slight negative charge. In contrast, the hydrogen atoms has a slight positive charge. These slight charges and the shape of water (bent - like the letter "v") make the water molecule polar (having two poles - positive and negative).
Most people know that opposites attract, so that is what happens here. The negative oxygen is attracted to the positive hydrogen atoms of other water molecules. This attraction is what causes a hydrogen bond to form. A hydrogen bond is not as strong as a covalent bond, but it is still very strong.
This hydrogen bonding in water is responsible for many of its unique properties like high surface tension (pain when you do a belly flop), evaporative cooling (why sweating cools you off), and many other unique properties. hi mr Morris and ms urez there my science teachers
What is the equation for power dissipated in a circuit?
The big power Formulas: Formula 1 - Electrical (electric) power equation: Power P = I × V = R × I2 = V2 ⁄ R
where power P is in watts, voltage V is in volts and current I is in amperes (DC).
If there is AC, look also at the power factor PF = cos φ and φ = power factor angle
(phase angle) between voltage and amperage. Formula 2 - Mechanical (mechanic) power equation: Power P = E ⁄ t = W ⁄ t
where power P is in watts, energy E is in joules, and time t is in seconds. 1 W = 1 J/s Scroll down to related links and look at "Formulas and calculations - Electricity and Electric Charge".
If the static charge has enough potential stored, there may be a risk of harm. Most commen occurances of static electricity being discharged is barley enough to sting the average human, leaving no permanent harm. Severe collections of static electricity, such as found in storm clouds, can discharge enough power to form lightening.
What are two types of resistance in mechanical energy systems?
Frictional resistance is a common type of resistance in mechanical energy systems, where moving parts rub against each other, converting some mechanical energy into heat. Aerodynamic resistance is another type, occurring when an object moves through a fluid like air, creating drag that opposes the motion and dissipates energy.
Examples of static electricity?
Sitting on a couch.
Shooting birds.
Eating trees.
Kicking dogs.
Smelling polar bears.
Watching porn.
Driving a cow.
Touching cacti.
Listening to octopi communicate.
Reading this.
All very good non-examples of static electricity!
How are convention currents formed?
Simple Answer:
When the driving force for convection is removed, the system will return to thermal equilibrium.
Explanation:
If convection exists in a fluid because a heat source is maintaining a temperature gradient and then that heat source is removed, the fluid will return to a stationary state with uniform temperature in a sequence of three overlapping stages.
1. With no driving force, the system initially continues the current flow and transport of heat, but the flow will slow and cease due to internal fluid viscosity
2. When system inertia of initial flow dissipates, new convection forces develop due to remaining thermal gradients and push fluid towards a configuration where density profile are perpendicular to gravitational forces.
3. Existing temperature gradients in the fluid will diminish through thermal conduction as the system proceeds toward a final uniform temperature.
What jobs does static electricity have?
Paint spraying cars: the paint particles are given a negative charge, and the car frame is given a positive charge, so the paint sprays out, and sicks to the car, and is attracted to all the hard- to reach areas
Electrosatic precipitator; in coal fired power station theses are used to stop the dust particles reaching the atmosphere. Particles of ass pass through a charged grid, and becone charged. They then stick to plated either side of this grid, where they can be disposed of safely
Photocopier; A charged drum is in the photocopier. Light is then shone through the paper, and whete ther is no print light hits the drum and it looses its charge. This leaves charge where there needs to be ink. Ink is the pulled onto the charged drum, and transfered onto paper
Antistatic floors; to avoid static charges in hospital, the floors are made out of an antistatic material, so no charge can build up.
What are the potential dangers of electricity?
The electricity in your home is dangerous. Many people have had an electric shock at some time or another without lasting injury but this does not show an immunity, merely the unpredictable nature of electrcity shocks. Slightly different circumstances could have resulted in death. it can easily kill people especially if you are young, old or sick. This is why all the wiring in a house has different forms of protection and is generally built into the walls, ceilings and floors.
- If you put something metal in a socket it could give you an electric shock.
- Keep water and drinks away from electricity and never take electricity into the bathroom. If you have wet hands you should not touch electricity, you should wipe your hands because you could get an electric shock.
- Do not let leads from electrical wires drag across the floor.
- If you leave a light bulb on you can burn yourself because it can be very hot.
- Do not put flammable materials on hot things as they could burn.
- Never leave fire by electrical items.
- Batteries are less dangerous than using plugs.
- If you plug too many plugs just in one socket then it may get over heated and catch fire.
high voltage: this is defined in national and international standards as being in excess of 1000 V ac or 1500 V dc.
D A Woolgar
In case of unity Power factor
- One Watt is = 1 Volt - Amp (from the formula P = I x E),
- One kilo Watt is a kilo Volt Amp.
- 1 kW = 1 kVA
For PF = 0.8, 1 kVA = 0.8 kW
Where does charge resides in case of conductors on surface or everywhere volume also?
charges reside only on the surface of a solid conductor. here charges maeans the charges which are free to move inside the conductor. we know very well that any particle or body always tries to acquire minimum potential energy. because the charges will acquire min. P.E only when they are on the surface.
Why will dust be attracted to a CD wiped with a dry cloth?
Dust will be attracted to a CD wiped with a dry cloth because it generates static electricity. This in turn causes dust to be attracted.
What are the best websites for science revision for ks3?
KS3 is one of the UK's education levels.
KS3 bitesize science is really good for revision. The link is below.
and sam learning. Your school teacher should be able to give you login details.
You can visit igcsechem.webs.com (advanced) or ks3science.webs.com (basic) to learn more chemistry!
What does a charged object exert on other charged objects?
It depends on what the charge is on both of the objects. If object 'A' is negative and object 'B' is negative, the two will repel or move away from each other. This is the same if both 'A' and 'B' are positive. However, if one is positive and one is negative, then the two will attract, or move closer.
How do you remove static electricity from clothes?
You can remove static electricity from clothes by using an anti-static spray, lightly misting the clothes with water, or using a dryer sheet when drying them. You can also try hanging the clothes to dry instead of using the dryer.
What is the difference between Free Electron Theory and Band Theory of solids?
Free Electron Theory:
This theory tells that, metals conduct electricity because of the presence of free electrons in it. The outermost shells of metal atoms will be loosely bound with their nucleus. So the electrons in it are free to move anywhere in the solid.These electrons are called free electrons and they are responsible for the conduction of electricity.
Band theory of solids:
A solid is assumed to contain many bands in which the electrons in it are packed. The most important are valence band and conduction band. The energy of electrons in these bands will be different.The difference in energies of valence band and conduction band determines whether the solid is a conductor, semi - conductor or insulator.For insulators, the difference between energies of them ( energy gap ) will be very high, and for conductor, these bands overlap each other.
The conduction band carries the electrons that conduct electricity, but the valence band has all the electrons in the ground state. Whether they go into the conduction band depends on the temperature and the energy gap between the bands. In a conductor, these bands overlap, and hence many electrons can become conducting. Thus, Band Theory explains distinction between metals and insulators, which Free Electron theory cannot do (since it assumes all valence electrons become conducting). Calculations are be performed to see which materials will have big energy gaps and which will have overlapping bands.
A seismogram is a recording of ground motion at a particular ground location, as collected by a seismometer. Multiple seismograms, taken from different locations, can be analyzed to determine the magnitude, depth and location of an earthquake.
Seismograms used to be recorded on paper by seismograph machines, but virtually all seismograms are recorded digitally, today, since computers are essential to accurately process the simultaneous readings from hundreds of seismometers.
Do balloons have static lightricity?
Balloons themselves do not generate static electricity, but when rubbed against certain materials, like hair or clothing, they can accumulate a charge. This can cause them to stick to surfaces or be attracted to other objects.
Wood is a good insulator because it contains air pockets within its cellular structure which limit the transfer of heat energy. Additionally, wood is a poor conductor of heat due to its molecular structure, which makes it difficult for heat to pass through it. This combination of factors makes wood an effective insulator for maintaining temperature in buildings.
