Electricity Definition and 999 Threads

1. What is the electric field magnitude midway between charges of Q1 = 2 C and Q2 = 9 C separated by 2 m? 2. How much work does a 9 V battery do in pushing 9 mC of charge through a circuit containing one lightbulb? 3. Points A and B each have an electric potential of +3 V. How much...

Homework Statement list 3 ways of wireless electricity transmission and how??Homework Equations The Attempt at a Solution i got nothing =.=

Hi, All: My knowledge of physics is very rudimentary; please be patient. A friend of mine's father owns a small restaurant, asked me (as a math student) how he could save some money. All I could think of (not knowing much about either general economics nor restaurant business) was the use...

So I was looking for a hilarious quote off this thread: https://www.physicsforums.com/showthread.php?t=326659 for a lecture I'm doing for electricity. Now, I've always been told that it's the current that kills you. However, this thread gives me the impression it's the frequency that can kill...

I stumbled across what I thought an interesting comparison of the costs to generate electricity from the US Department of energy...includes transmission costs. http://en.wikipedia.org/wiki/Relative_cost_of_electricity_generated_by_different_sources Its shows the total cost per megawatt...

Hi, My book says the electrons must be pushed from the positive to the negative terminal, which means work must be done on the electrons. I find it a bit confusing. Is the book saying that because we are using the conventional current? Meaning that the positive end of the battery has a...

Let's saying you're working with something that has electricity running through it. If you ground yourself by touch something metal, aren't you making it easier for charge to flow through you through the metal, so a greater charge would flow through you? And if you didn't touch something metal...

As we know, plastic is non-conductor, iron metal is conductor, does anyone have any suggestions on what kind of property in term of molecule structure allows electricity to get through? Thanks in advance for any suggestions

Homework Statement " The result of an imbalance of this "fluid" (electrons) between objects is called static electricity. It is called "static" because the displaced electrons tend to remain stationary after being moved from one insulating material to another." Homework Equations...

I have a problem that is costing me lots of $'s. I built a pole barn seven years ago that is about 50 feet from my house and garage. I am on my third garage door opener due to logic boards being destroyed by static electricity. I have had a second electrician check out my wiring and he says...

The idea I have is that on a multi fuel stove I could have a boiler attached to it to heat water for the purpose of steam, then the steam in turn to drive a small steam turbine to produce electricity and the steam then to condense and return to water. Thus allowing the process to start again...

Current Electricity -- current flowing through hand Homework Statement i)For a layer dry skin 1mm thick, determine the resistance of a 1 cm^2 area of skin. Resistivity of dry skin : 3 x 10^4 ohms m [3.0 x 10^5 ohms ] ii)A person, who is well-earthed, accidentally grabs a wire of...

Electricity "True, Apparent and Reactive power" This is the problem: "The power factor of a load on 120 volt, 60Hz source is raised from 0.707 to 0.866 power factor lagging by connecting a 53 micro-farad capacitor across the load. How can i solve for the "true" power?" i know that power...

I apologize for my very basic question, but I cannot find a straight forward answer anywhere. I want to know "Physically, what are volts". I understand that amps are a count of electrons passing a point in one second. I know the formula for Ohm's law, but that still doesn't answer the question...

Nuclear power plants as well as power plants in general are not self-sufficient in terms of electricity. If a nuclear power plant loses outside electrical power, the plant must then be powered with emergency diesel generators which typically have about 10-12 hours worth of fuel, and then...

We're told that by switching off your geyser when you're not using it, like during the day when you're at work, saves electricity, but is this correct? When you keep switching your geyser on and off it has to keep heating up cold water, but when you have it on all the time it maintains it at...

Hello, in water NaCl break itself into positive and negative ions but i didn't understood how exactly works the electricity conductions... the negative ions go to positive so seen that they are negative shouldn't repel the flow of electricity causing no conduction? thanks!

Hi Friends, a high quality submersible water pump from Italy, it is 220 volt, 1,100SA, 4.3 amps, and it is grounded into the Earth while in use; and we also have an emergency electrical cut-off that cuts the power in case of an electrical short; but the question is, in a new high quality pump...

I am trying to find out how much it costs to make synthetic fuels from electricity and appropriate feed stock. Some fuels that are interesting are methanol and dimethyl ether. Any pointer to books or article or info is appreciated.

Hello. I've been reading numerous texts about mains electricity but I'm not getting some of the things. I'll start with some questions, considering Live, Neutral, and Ground wires. 1) Does the neutral wire return/come from the supply company? In that case, where does the company connect the...

i want to generate electricity from piezoelectric load cell by application of load on it, but i don't know which type of cell to use and from where to get it? i want good efficiency, please help me out.

So I'm sitting here, reading about different ways to create gravitational fields as well as messing around with random thoughts and ideas, and this question comes to mind: Would greater electricity affect a gravitational field created by an electromagnet? Anyone who knows? I'd really like to...

Storing energy in flywheels is old. But at a cost competitive with the power grid is uncommon. And low losses over half a day storage, using affordable technology, hasn't been done, I believe. Links to my enabling technologies (drawings need to be logged in, sorry): A cheap flywheel material...

I have been reading and it came to my attention that it is more effective to generate electricity at a 60Hz cycle that it is at a 50Hz cycle. Yet only a minority of countries generate electricity using 60Hz. Why is it most countries generate their electricity at a 50Hz cycle when it is known...

Before i start my question , i have to mention that I'm only a beginner for physics and chemistry , if possible , please explain in the way that easier to be understand. In simple cell , 2 different metals are immersed in an electrolyte and connected to ammeter , the metal which is more...

This is a question that was on my test Homework Statement http://img269.imageshack.us/img269/5125/circuitthingy.jpg In the circuit in the drawing switch S is open. Both resistors are idential, both having resistance R each. Given the source is E, and R = r (the resistance of...

Homework Statement A wire carries a current of 2.0 A for 1.0 hour. How many electrons pass a point in the wire in this time? A 1.2 x 10-15 B 7.2 x 103 C 1.3 x 1019 D 4.5 x 1022Homework Equations Q=I/tThe Attempt at a Solution Q=2(60)=120 number of electrons= 120/1.60217733 × 10-19= but the...

air, glass, mica, rubber, water, etc all are insulators because they don't have free charges to carry the current... I don't understand what do we mean by "carry"?? i mean, i don't really understand what happens at the micro level during electrical conduction through a medium...How do the...

A friend sent me this 2.5 minute video and asked if I can explain it. It's not even a complete circuit but the light illuminates! I'm sure this is a hoax, but can anyone explain how it is faked??

Hello world. Recently, I've started diving into the world of magnets. Here is a rough drawing of my experiment (not homework/coursework, simply doing it for personal interest) (I have found the items on ebay and what not, just creating the ideas before purchasing the magnets and other items)...

Killing bamboo plants with electricity?? This might be a crazy idea but I'm wondering if it's possible to kill bamboo roots with electricity. I have a bamboo bush that I pulled but the remaining roots will sprout new plants. Bamboo plants are hard to kill. Would I be able to kill the roots...

Free unlimited electricity in space?? A Changing Magnetic Field Produces Electricity. Suppose we build a huge coil in space and place a strong magnet in between.We then provide an external spin to the magnet.In space,there is no opposing force.thus,according Newton's first law,the magnet will...

0.16 amps from a dry battery for 10 minutes, according to the severity of an electrical current was received during this time wearing zinc a) Find the number of atoms. b) Find the mass. i don't know english and i translate the text from turkish by google translate. please answer this...

Why doesn't static electricity cause ionic bonding,since some atoms become positively charged and others are negatively charged ?

there is A , B and C A- is a small powered boat blade B-is a piece of 1 to 1/2 inch glass C- is the power (i don't know how it will power it yet) ------------------------ So how is it possible to have a motor send electricity though the glass to power the small blade? what would i...

hey all, i recently had an idea to combine the concepts of a magnetic bearing i.e. using the repulsion of magnets to lift a rotating object so that the object may rotate without mechanical friction , as well as an axial-flux alternator where coils of wire are exposed to a regularly fluctuating...

Scenario: If a human body is fully charged with positive electrons (protons/lack of electrons) and comes in contact with a pool of positive electrons such as a charged plate, the charge stays the same in the human body and the plate. Now if the human comes in contact with a source of negative...

Hi, I had a question in my exam at my college that I did not quite know how to answer. Why is the study of magnetism more important than of electricity in technology ? (I can't remember exactly the question)

Homework Statement Four point charges have equal magnitudes. three are positive and one is negative, as the diagram shows. they are fixed in place on the same straight line, and adjacent charges are equally separated by a distance d. consider the net electrostatic force acting on each...

I know I have read something similar to this topic in the forums a few times over and found most of the responses to be rather narrow in the understanding of the concept as well as the execution...While yes many raised a lot of valid concerns that when looked at as a singular issue would spell...

The local electric supply in our country is 415 volts. Our company recently imported plant and machinery. All the motors and electric panels that have been imported are on 220/110 volts specifications. The total load of the motors is 110 Kw. The motors are now tripping as soon as they are...

I'm currently in an electricity and magnetism physics course and we're using the 8th edition of Serway. I'm looking for a review type book that focuses on problem solving with examples and explanations rather than theory. Here are the topics we are covering throughout the course: 23...

Hello everyone. I think I have a major misunderstanding about the nature of batteries, and just the basic concept of electricity. I would really appreciate your help in straightening some things out. So I’m just going to leap right into the questions. 1. So a battery emits electrons from...

Hello everyone! I was just thinking about whether it will be possible to utilise the energy transmitted through the radio waves to produce back electricity for a household. Most of the houses in the world are blanketed by radio waves from all directions. Will it be possible to use an antenna...

Hello: Many many years ago I walked away from community college with an associates degree in physics, and despite my fondness for the subject, I had to put it aside for other things. I recently happened upon something that lead me to realize how much I had forgotten, and so I've decided to...

Homework Statement 1. For the circuit shown in Figure Q1 calculate: (i) The magnitude and direction of the current that flows through Rl , (H) The magnitude and direction of the current that flows through RS. (iii) The potential difference between nodes Q and R (iv) An equivalent circuit...

Yes, yes I know about the template, but these questions are so basic that I don't really know what I can show as work... Sometimes all I need for help is the relevant equation itself -.- So please don't delete or hate. Thanks! 2. http://tinyimage.net/images/50136173150204648365.png The...

I have two problems that I have difficulty understanding and solving. Homework Statement The operating efficiency of a 0.5 A, 120 V electric motor that lifts 9 kg mass agaisnt gravity at an average velocity of 0.5 m/s is most nearly what percentage? Please help me solve this problem 2...

this is like 1800s technology for most parts