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What happens to charge and potential difference and capacitance in the presence of dielectric when the battery is disconnected from the capacitors?
Wiki User
∙ 12y ago
The capacitor will hold the charge, until it leaks off due to resistances in the dielectric or external.
Wiki User
∙ 12y ago
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What is difference between capacitor and super capacitor?
Super capacitor have high capacitance compare to normal capacitor. Super capacitor use two layer of dielectric medium whereas in normal capacitor single medium dielectric. Because of this super capacitor use as alternate power source for RTC when computer is off.
What is the difference between electrolytic capacitors and normal capacitors?
because normal capacitors does not have any polaririties.
Difference between stray and parasitic capacitance?
Parasitic capacitance is unavoidable and usually unwanted capacity between two or more conductors which exists due to close proximity and which typically causes non-ideal circuit behavior. Stray capacitance, as it is typically thought of, is a type of parasitic capacitance. It is the capacity from a conductor to its surroundings which is the aggregate of the conductors in its environment inversely weighted by the distance to each of the environmental conductors.
What is difference between impedance and reactance?
Impedance is the net reactance(for Capacitors and inductors in the circuit) / Resistance of the circcuit whereas reactance is the prperty of the individual passive components ( only capacitors n inductors) to resist the flow of charge.
How does a capacitor work?
In a way, a capacitor is a little like a battery. Although they work in completely different ways, capacitors and batteries both store electrical energy. Inside the battery, chemical reactions produce electrons on one terminal and absorb electrons on the other terminal. A capacitor is much simpler than a battery, as it can't produce new electrons -- it only stores them. Inside the capacitor, the terminals connect to two metal plates separated by a non-conducting substance, or dielectric. You can easily make a capacitor from two pieces of aluminum foil and a piece of paper. It won't be a particularly good capacitor in terms of its storage capacity, but it will work. In theory, the dielectric can be any non-conductive substance. However, for practical applications, specific materials are used that best suit the capacitor's function. Mica, ceramic, cellulose, porcelain, Mylar, Teflon and even air are some of the non-conductive materials used. The dielectric dictates what kind of capacitor it is and for what it is best suited. Depending on the size and type of dielectric, some capacitors are better for high frequency uses, while some are better for high voltage applications. Capacitors can be manufactured to serve any purpose, from the smallest plastic capacitor in your calculator, to an ultra capacitor that can power a commuter bus. NASA uses glass capacitors to help wake up the space shuttle's circuitry and help deploy space probes. Here are some of the various types of capacitors and how they are used. Air - Often used in radio tuning circuits Mylar - Most commonly used for timer circuits like clocks, alarms and counters Glass - Good for high voltage applications Ceramic - Used for high frequency purposes like antennas, X-ray and MRI machines Super capacitor - Powers electric and hybrid cars Capacitor Circuit In an electronic circuit, a capacitor is shown like this: When you connect a capacitor to a battery, here's what happens: • The plate on the capacitor that attaches to the negative terminal of the battery accepts electrons that the battery is producing. • The plate on the capacitor that attaches to the positive terminal of the battery loses electrons to the battery. Once it's charged, the capacitor has the same voltage as the battery (1.5 volts on the battery means 1.5 volts on the capacitor). For a small capacitor, the capacity is small. But large capacitors can hold quite a bit of charge. You can find capacitors as big as soda cans that hold enough charge to light a flashlight bulb for a minute or more. Even nature shows the capacitor at work in the form of lightning. One plate is the cloud, the other plate is the ground and the lightning is the charge releasing between these two "plates." Obviously, in a capacitor that large, you can hold a huge amount of charge! Let's say you hook up a capacitor like this:Here you have a battery, a light bulb and a capacitor. If the capacitor is pretty big, what you will notice is that, when you connect the battery, the light bulb will light up as current flows from the battery to the capacitor to charge it up. The bulb will get progressively dimmer and finally go out once the capacitor reaches its capacity. If you then remove the battery and replace it with a wire, current will flow from one plate of the capacitor to the other. The bulb will light initially and then dim as the capacitor discharges, until it is completely out. Farad A capacitor's storage potential, or capacitance, is measured in units called farads. A 1-farad capacitor can store one coulomb (coo-lomb) of charge at 1 volt. A coulomb is 6.25e18 (6.25 * 10^18, or 6.25 billion billion) electrons. One amprepresents a rate of electron flow of 1 coulomb of electrons per second, so a 1-farad capacitor can hold 1 amp-second of electrons at 1 volt. A 1-farad capacitor would typically be pretty big. It might be as big as a can of tuna or a 1-liter soda bottle, depending on the voltage it can handle. For this reason, capacitors are typically measured in microfarads (millionths of a farad). To get some perspective on how big a farad is, think about this: • A standard alkaline AA battery holds about 2.8 amp-hours. • That means that a AA battery can produce 2.8 amps for an hour at 1.5 volts (about 4.2 watt-hours -- a AA battery can light a 4-watt bulb for a little more than an hour). • Let's call it 1 volt to make the math easier. To store one AA battery's energy in a capacitor, you would need 3,600 * 2.8 = 10,080 farads to hold it, because an amp-hour is 3,600 amp-seconds. If it takes something the size of a can of tuna to hold a farad, then 10,080 farads is going to take up a LOT more space than a single AA battery! Obviously, it's impractical to use capacitors to store any significant amount of power unless you do it at a high voltage. Applications The difference between a capacitor and a battery is that a capacitor can dump its entire charge in a tiny fraction of a second, where a battery would take minutes to completely discharge. That's why the electronic flash on a camera uses a capacitor -- the battery charges up the flash's capacitor over several seconds, and then the capacitor dumps the full charge into the flash tube almost instantly. This can make a large, charged capacitor extremely dangerous -- flash units and TVs have warnings about opening them up for this reason. They contain big capacitors that can, potentially, kill you with the charge they contain. Capacitors are used in several different ways in electronic circuits: • Sometimes, capacitors are used to store charge for high-speed use. That's what a flash does. Big lasersuse this technique as well to get very bright, instantaneous flashes. • Capacitors can also eliminate ripples. If a line carrying DC voltage has ripples or spikes in it, a big capacitor can even out the voltage by absorbing the peaks and filling in the valleys. • A capacitor can block DC voltage. If you hook a small capacitor to a battery, then no current will flow between the poles of the battery once the capacitor charges. However, any alternating current (AC) signal flows through a capacitor unimpeded. That's because the capacitor will charge and discharge as the alternating current fluctuates, making it appear that the alternating current is flowing.
Which type of conductors are used in capacitors?
The conductors in capacitors are typically made from thin plates (or foil) of very ductile metallic materials to get the most capacitance. These materials must also be inexpensive and widely available. Aluminum is typically the workhorse material for most conductors in capacitors. Tantalum is used as well for the Cathode plate. Silver is also appears in silver-mica capacitors, and are used for high-accuracy audio applications. I believe that Manganese Dioxide MnO2 is sometimes used, as well, for the anode plate. A capacitor is a passive electronic component consisting of a pair of conductors separated by a dielectric (insulator). When there is a potential difference (voltage) across the conductors, a static electric field develops in the dielectric that stores energy and produces a mechanical force between the conductors. An ideal capacitor is characterized by a single constant value, capacitance, measured in farads. This is the ratio of the electric charge on each conductor to the potential difference between them.
What is the part of capacitor?
Capacitors consist of a insulating material, called a 'dielectric', sandwiched between two conductors, called 'plates'. Capacitors are devices that store energy(not charge!); this energy is stored in the electric field set up within the dielectric between the two plates when they are connected to an external potential difference.
What is difference between capacitor and super capacitor?
Super capacitor have high capacitance compare to normal capacitor. Super capacitor use two layer of dielectric medium whereas in normal capacitor single medium dielectric. Because of this super capacitor use as alternate power source for RTC when computer is off.
What is the difference between monolithic ceramic and mutilayer ceramic capacitors?
Ceramic Multilayer vs Monolithic CapacitorBoth multilayer and monolithic capacitors have multiple layers. The main difference between the two is the manufacturing process. Monolithic capacitors have a paste of ceramic material applied between the conductive layers. After this paste is applied the capacitors are then baked. Multilayer capacitors have the ceramic material sprayed onto the conductive layers. This generally means that monolithic capacitors can't go as high in capacitance because the amount of layers is limited due to their manufacturing process.
What will happen when a dielectric slab is inserted in the parallel plate capacitor?
(a) Charge Will increase (b) Potential difference will stay the same (c) Capacitance will increase (d) Stored energy will decrease
Difference between electrolytic and non-electrolytic capacitors?
Electrolytic Capacitors:1. It provides high capacitance in small volume.2. It has got polarity.3. It is not suitable for high frequencies due to losses in dielectrics.4. It is generally available in 1-100 µF rangeNon-Electrolytic Capacitors:1. Its capacitance depends on dielctric constant of the bulk.2. It doesn't have polarity.3. It is widely used at all frequencies.4. It ranges from pico Farads to fractions of µF.
Difference between ceramic and electrolytic capacitors?
In ceramic capacitors the dielectric is a thin layer of ceramic and both plates are metal foil. These capacitors are unpolarized. These capacitors have negligible internal inductance or resistance.In electrolytic capacitors the dielectric is an ultra thin layer of corrosion on the surface of a metal foil plate and the other plate is an electrolyte paste. These capacitors are polarized and if connected backwards are likely to explode. These capacitors have significant internal inductance, making them bad filters of noise in the MHz range and above which requires ceramic capacitors.
What is the difference between electrolytic capacitors and normal capacitors?
because normal capacitors does not have any polaririties.
What is the difference between capacitance and capacity?
Capacitance is quite literally the capacity to hold charge at a given potential difference.
What is the difference between capacitive reactance and capacitance?
Capacitance is a physical characteristic of a pair of conductors, dependent upon the distance between them, the opposing cross-sectional areas of those conductors, and the nature of the dielectric between them, and is measured in farads.Capacitive reactance is the opposition to the flow of current of a circuit, determined by that circuit's capacitance and the frequency of the a.c. supply applied to that circuit, and is measured in ohms.
What is the difference between complex permittivity and static dielectric conatant?
What is the difference between complex permittivity and static dielectric conatant?
What is difference between lumped and distributed elements?
simply defining Lumped elements are components available in market i.e., resistors,capacitors,inductors...... Whereas Distributed elements are inbuilt property( resistance,capacitance,inductance )of a connecting wire
