Angelina Jolie

How can I measure the length of the wire in a circuit more accuratly?

I have set up a circuit to of a power pack, ammeter and voltemeter to measure the resistance of a wire, and how this is affected as the length of nicrome wire decreases.

I have attached the wire to two crocodile clips, and then I move them down the length of the wire to alter the length, using a ruler to measure

How can I make more accurate mesaurment of the length, to reduce the uncertainity in the measuremt, what instruments can I use that can measure to a greater precision
Please help me

how to make voltage divder for 3 3v adapter from 9 volt. dc power supply?

I have 9 volt dc power supply battery derived from 230 v line voltage. I already run 3 multimeter parallely from the 9 volt. output of the battery. now i want to connect the three adapter of multimeter each require a 3 volt dc. but when i made a voltage devider with a 470 ohm and 300 ohm (voltage across 300 ohm resistror is 3.5 v and across 470 ohm it is 5.4 v) and and connect it to the same 9 volt output to which already three multimeters are connected and connect the only one adapter across the 300 ohm resistor it had not became on. now when i connect a single adapter across 470 ohm resistor it became on. then after when i connect a second adapter to the 300 ohm resistor with a first one also connected, first time only one adapter becames on… second time when i connect none of the two adapter became on. Now when i connect a both the adapter across the 9v output of the battery at which three 9 v multimeters connected, both the adapter becomes on. quwstion is I have to connect a three such adapters to the same battery output, what should i do. normally adapter runs on a two 1.5 v pencil cell, if i connect a three adapter to 9 v. battery is there any scope of damaging of multimeter in future??????????

question about electric circuit?

Discuss the advantage of the Wheatstone bridge over an appropriate “ammeter-voltmeter” combination in calculating an unknown resistance.

gfci outlet not working?

Inside my garage I have multiple outlets on 1 circuit. All GFCI’s test properly (press the test, and the red light illuminates). Once you reset it it goes out.
I have 1 exterior outlet on that same circuit. When I test it, the red light does not illuminate. Using the multimeter, the power does go out when you press test. (i tried a new GFCI outlet, and the same problem happens).
Any ideas.
I checked the wiring from the outlet in my garage going to the outside outlet (the problem one). All is wired correctly.
When you press the test the red light is suppose to illuminate. It does not illuminate. That’s the problem. I don’t know why it is not illuminating.
Since the outlet works (minus the gfci light test), would you assume it would be my ground I need to replace or the neutral? or do i need to troubleshoot both?

Voltage across a capacitor.?

Given a stopwatch and a voltmeter, how do you think you could measure characteristic time T in that case? (Remember that the voltage source is a DC one, like a battery, and you can charge the capacitor and by plugging out the source let it discharge while you are measuring its voltage)

ANALOG MULITMETER REPAIR QUESTION?

I have an analog multimeter that works just fine…….well, almost.

Everything works great EXCEPT for ONE scale on the DC ammeter selection. 50 microamps works great, 25mA works great, 250mA works great.

The 2.5mA scale is the problem child. I place the meter in series with a carefully calibrated circuit that SHOULD show 1.25mA on the meter…………whoops…..it pegs the needle. Where/what do I look for to fix this problem???

PS: I do not think the problem involves the meter movement, it is very accurate on scales besides the broken one.

THANKS!!!!!
Thanks a lot for the help.

The shunt resistor was the problem. The OHMs on the shunt was supposed to be 102-ohms…….it was 749K-ohms. Replaced it and my cheapo meter is now working like a charm.

The shunt resistors are kinda wimpy….1/4 watt(unfused). I bet I fried that sucker by stupidly trying to read a high current through that sucker and it darn damaged it. I examined the bad resistor before I removed it……no visual signs of damage.

PS: I will award the first answer the “best answer” award later in the week!!!

Using sine wave analog multimeter to read square waves?

Here is my homework problem:

“If the AC voltage of a square wave is read using an inexpensive analog multimeter calibrated for sine wave input only, what would be the expected percent error?”

I think I’m supposed to look up specs of a cheap analog multimeter maybe? But even if I do that, I’m not sure how to produce an answer. Please help, thank you smart people of the world for spending your time helping a college student.

PHYSICS Distinction level question. Someone Help me out please?

So I have been doing this practical in lesson.

Here is what I wrote for the Merit part.

I have used the micrometre, rather than the vernier callipers or metre rule to measure the diameter of the wire because the micrometre measures to the nearest 100. It is more accurate and the results then are more reliable.
I have used an ohmmeter in one on my methods. This is because an ohmmeter gives you a quick and easy result in the experiment. It’s very simple to use and clear to read.
In other part of my scientific experiment, I have used an ammeter/milliammeter and voltmeter. An ammeter is very precise. It gives you a more accurate answer so the results become correct. The voltage/ammeter also gives more accurate answers.
The choice of shunts / scales I used was the 1 Volt scale. It is really quick and simple to read and to record the results. This is because there is only one needle which uses the whole scale. .
The ammeter/milliammeter is more suitable than an analogue meter to measure current through the wire in the experiment. This is because there was no parallax error on the digital scale, and on the analogue meter shown this error during the experiment. A parallax error means looking from a different angle.

The QUESTION FOR THE DISTINCTION now:

Evaluate the variables in operation of instruments used and how they could be optimized. ( How they can be used in the most effective way).
For your methods , explain the actions you undertook to ensure accuracy and precision. Your discussion should include both practical steps taken and analytical techniques used and the reason for these actions.

Can Anyone Help me out?

Thank you!

Is an oscilloscope required for making a synthesizer?

I want to build this analog synthesizer kit. (See link below). However, the website says one has to have an oscilloscope. Is that true? If so, what frequency? Is it possible to use a computer as an oscilloscope? (I have a BA in Math and another in computer science, a first year physics course and a high school electronics course. However, I have only build a few small circuits and only have a digital multimeter and a breadboard.)

http://www.musicfromouterspace.com/index.php?MAINTAB=CATALOG&CATPARTNO=SLMSMARKII_COMBO2&VPW=1277&VPH=731

What multimeter should I get for my technical theatre major?

I am looking for something that is not too expensive but will be able to handle the amperage/voltage etc of stage lighting.