Charging Definition and 407 Threads

[b]1. i have the answer, but just don't understnad it A small metal ball is given a negative charge, then brought near (i.e., within a few millimeters) to end A of the rod. What happens to end A of the rod when the ball approaches it closely this first time? Select the expected behavior...

hi am going to do my mini project this feb...i have chosen this as my topic.. if anybody has information about this topic it may be of greater help...you can also give suggestion about some advanced technology in this particular field...

Homework Statement Initially, sphere A has a charge of –10e and sphere B has a charge of +20e. The spheres are made of conducting material and are identical in size. If the spheres then touch, what is the resulting charge on sphere A? a) +10e, b) -10e, c) -5e, d) +5e The attempt at a...

Hi, This is my virgin post. This forum has been a great source of information for the past one year. I am a high school teacher from Singapore. In the study of electrostatics (more specifically induction), we often encounter the scenario below: Two insulated metal spheres touching...

**EDIT: I solved the second part of the problem, I just need help on the syntax for the 2 equations of q(t) and I(t). Homework Statement http://img262.imageshack.us/img262/2139/phys1xf8.jpg Homework Equations First Part: q(t) = Q(1-e-t/RC) I(t) = (emf/R) e-t/RC The Attempt at a Solution...

If eight flashlight batteries in series have an emf of about 12 V, similar to that of a car battery, could they be used to start a car with a dead battery? Why or why not? My friend posed to me this question and then I just sort of stumbled and was dumbfounded. I answered it by saying the...

Homework Statement Two uncharged spheres are touching (they are held by insulating stands). A negatively charged rod touches the sphere on the left. After, rod is taken away and the adjacent sphere (the one that the rod did not touch) is separated. What are the net charges on each sphere...

I have a 19V 3.42A laptop charger, I cannot charge my laptop with it .I hae checked for continuity and its clear the cable is not broken and the charging voltage is 19V but somehow it doesn't charge my laptop.But other chargers work fine.Whats this miracle in Science I can't understand.

Hey, everyone. Just a quick question here. If I have the following circuit, with it's switch initially opened, what will happen to the current through resistors 1 and 2, after I close the switch? http://img249.imageshack.us/img249/7716/showmeplkh6.gif 1) When the switch is first closed...

how do automatic battery chargers in cell phones work? pleasezz give me a detailed explanation on this , as i couldn't find information on the net

Is there someone here who have a good link for the charging curve of a lithium copper oxyphosphate battery. Thanks.

hi... i have a thought in advance, that i can charge my cell phone through solar energy itself . actually I am doing my activities regarding that... giva me some suggestions which is helpful for me.. and i want to know why this is still not in market..my project is reasonable or not ?...

Hi - I am trying to calculate the power required to charge a battery in order to compare the energy requirements of an electric scooter versus an internal combustion scooter. The electrical scooter specifications state: battery: 12V/50AH x 4 time to 90% charge: 4.5 - 6 hours charger: 400W...

Homework Statement You observe that a negatively charged plastic pen repels a charged piece of magic tape. You then observe that the same piece of tape is repelled when brought near a metal sphere. You are wearing rubber soled shoes, and you touch the metal sphere with your hand. After you...

one capacitor is charged with a battery. then the capacitor is disconnected away from the battery. Then, the capacitor is hooked up to another capacitor. the result involves losing of energy to thermal radiation and light as the charges from one capacitor moves to the other capacitor...

I gassed up today at what used to be a Unocal. It is now an independent station. The gas was 9 cents per gallon more for those paying with a credit card. It is automatically added at the pump if people swipe a credit card. Cash and debit were 9 cents less.

hi, I'd just like some advice on how best to charge a 70 amp hour deep cycle battery from a cigarette lighter socket. I use the battery to run my 35 litre waeco fridge when I'm camping for a couple of days, but would then like to charge the battery while travelling. I'm guessing a flat 70AHr...

Homework Statement A small positively charged sphere is lowered by a nonconducting thread into a grounded metal cup without touching the inside surface of the cup. The grounding wire attached to the outside surface is disconnected and the charged sphere is then removed from the cup. What best...

http://img230.imageshack.us/img230/8480/circuitbb5.th.gif Switch 1 is turned on until the 12 microF capacitor is completely charged. Then Switch 1 is switched off, while switch 2 is switched on. How do you write a differential equation that may be used to find charge on the 4 mircroF...

How would I go about upping the voltage from 12V to 300-400V for charging capacitors

Ok, so my phone died :( and my outlet charger is broken so I charge it thru the USB. Does my computer have to actually recognize my phone in order for it to start charging it? I've had it hooked for an hour now ... but it still hasn't turned on even for a second.

Please help me with this question. Thanks... i read from book that in order to charge an uncharged capacitor, we have to connect the capacitor and a resistor with high resistance in series to a battery with emf E. I don't understand what is the use and the effect of the resistor in this...

when you charge a capacitor (camera flash for instance) you hear a sound that increases in pitch and dies out i wonder what causes that ? i think you also hear in on tv when they charge the defibrillator before they zap someone to restart the heart

If you have the positive terminal of a battery connect to a switch then to one plate of a parallel plate capacitor and the negative terminal connected to the other plate, what happens when the switch is still open? Does charge build up on the bottom plate of the capacitor only or does nothing...

A 12-V battery with internal resistance of 0.02 Ω is used to charge a battery with an emf of 10.5 V and an internal resistance of 0.15 Ω. What is the charging current? We don't have any examples in the book or class notes about connecting 2 batteries of differing voltages in parallel. My...

I have a couple of different lithium ion battery packs. On one pack charging current reads 0.1 amps, and on the other 1.5 amps. I already charged the 0.1 amp pack with 0.1 amps, and seems to be working. Now, I'm sort of weary charging the other pack with 1.5 amps. Doesn't that seem too much...

I was doing an experiment to determine the capacitance of a capacitor in a circuit with a particular resistor R. This was also set up to an oscillator and oscillscope. Now t=RC, where t is the time constant. At a time of t, the value of V across the capacitor is .63(V_0), says my guide. So if...

Gentlemen and Ladies - Requesting a little clarification on this. Heres the setup: I have "steady" voltage source - In this case from a battery (Vb) Have three capacitors (C1, C2, C3). Have 2 Resistors R1 and R2. Here are the relationships: Capacitance Voltage...

Homework Statement A 1.47 micro F capacitor is charged through a 123 Ohm resistor and then discharged through the same resistor by short-circuiting the battery. While the capacitor is being charged, find the time for the charge on its plates to reach 1/e of its maximum value. Homework...

Consider a simple circuit where resistance R is connected in series with a capacitor C and a voltage source V. The switch is connected at t=0. After t>>RC, the capacitor is fully charged with energy Es=1/2*CV^2 and R dissipates energy of Ed=1/2*CV^2. Question. 1) How can one design a...

given an arbitrary circuit when can u say that a given capacitor of course in the circuit has been fully charged

Hey guys, I was thinking about the possibility of charging a device, such as a battery, through wireless means. Does anyone know if there has been any research in this area? Or perhaps a method already in existence? I was thinking that perhaps you could use light to heat up a receiver...

i read about a month ago that cell phone charging is about to be 'revolutionized.' Apparently, cell phones of the near future will have a wireless charging system where you plug a radio transmitter into the wall, and the cell phone receives the signal and uses it to charge it's batteries. My...

Suppose you let identical pith balls come in contact to make q1=q2. Would the charges be equal if the pith balls were of different size?

Charging current?? i have a question that says a generator is charging a normal battery the internal resistance of the generator and battery are given, and i must calculate the charging current how might this be done? generator is 30v with 4 ohm internal resistance. battery is 24v with a...

In the following schematic, will the RC time constant be the same for all capacitors using the equivalent resistance of all the resistors? When I plug it into pspice or electronics work bench, it has that the First capacitors voltage as a function of time will always be twice as much as the...

Hi, Given that a " up " quark has charge of 2/3e ; a "down" quark has a charge of - 1/3e, where e is the elementary charge (+1.6 x 10^-19 C). can is say that a proton contain 3 " up " quark and 1 "down" quark? the charge in the end seems to add up to +1. is what is have said correct...

Hi guys, I've been reading the forums and finally I have something to post :smile: I've got a question regarding charging parallel plate capacitors. Take this for example: Connect a 6 Volt power supply to a resistor of 2Mohm and in series with a 15uF capacitor initially uncharged, with...

Problem: "A 12.0 V battery with an internal resistance of .02 Ohms is used to charge a battery with an emf of10.5 V and an internal resistance of .15 Ohms. What is the charging current?" Question: I'm pretty much stuck on the set up of this problem. I know how to find the current if...

Ok. So putting capacitors in series decreases the capacitance of the circuit (and correct me if I'm wrong any where in this, and I'm likely to be). So this would mean it would take less time to charge, I'm assuming. What if you charged a set of, say 3, capacitors in series, then hooked them up...

the problem is: "Calculate the work that must be done to charge a spherical shell of radius R and total charge Q", and I have no idea where to start. You probably have to write some sort of an integral but I don't know how. Can anyone give me a hint?

What is the max current for a rapid sealed lead acid battery charger? Most recommend 0.1C up to 1C where C = Ah rating. I have a max 30-32A regulated 13.8VDC power supply and the battery is 12V, 170Ah. Would charging the battery at the max 32A damage the battery?

What is the max current for a rapid sealed lead acid battery charger? Most recommend 0.1C up to 1C where C = Ah rating. I have a max 30-32A regulated 13.8VDC power supply and the battery is 12V, 170Ah. Would charging the battery at the max 32A damage the battery?

I'm an electrical engineer, so I'm used to circuits and components and know them pretty well. What I don't know is "broken circuits"; the physics of a charged object hanging out in space by itself, discharging into other objects, etc. So I'd like to ask a few things that have been confusing me...

A battery is being charged by a voltage v=11+0.5t V and a constant current of 2 A. The price of a kWh is 10 cent. How much is 5 hours battery-charging? My work: p = 22 + t w= \int_{0}^{5} x dt = 25/5 + 22*5 = 122.5 W 122.5 W in 5 h = 5 * 122.5 Wh = 0.6125 kWh

I'm completely boggled by this problem: "A 12.0V battery is used to charge a 4.00μF capacitor. A switch is then thrown disconnecting that capacitor from the battery and connecting it to a circuit with two capacitors (3.00uF and 6.00μF) connected in series. What are the final charges on the...

elctron chart? does anybody know what the cart is that you look up if its takes or gives up electrons easily. you know for objects like ebonite rod, and fur. i printed it of the internet awaile ago and i can't find it so i would like to print it but i don't remember what it is called. thanks

So I have done most of this problem, but can't seem to find the final charge on that capacitor. It says that there was a switch, even though it is not in the image, and that at t=0 the switch is closed, and that the capictor had no charge initially. I solved for and know that I1 = 4.2 A, I2 =...

So according to my common sense and logic and some disscussions I had with other people on IRC, theoretically in space if you had a exactly/perfectly spherical planet with a cylinderical hole through it, and you dropped something -a huge permanent magnet to be specific- through that hole, the...

Just a quick question i wonder some one could help me with, when ions charge do they attract the charge in some way or does the charge have to be some how taken to them throught a thrid party reaction or process, and does enviorment have any affect in the charging process thankyou