# Tag Info

0

The number you have found for relative permeability is fine if you embed all the magnet into a piece of iron, then you will have a quite high field but you won't be able to "feel" it as it just stays inside the metal. What you are probably thinking to do is an iron core solenoid, where the magnetic field lines close into air. Then you need an effective ...

1

Typically a wire with higher resistivity is used e.g. Constantan. Then see the experiment here.

7

As others have noted, the big issue is getting the resistance of the wire into the range where your multimeter can measure it accurately. For that, the simple approach is to make the wires as long and thin as you can in order to maximize resistance. That said, another thing you can do is improve the precision of your measurements, e.g. by using ...

4

I did a similar experiment this year for my final science assignment. We used a transformer which had two long coils of copper wire inside, of different lengths (10m and 750m) and thicknesses. Pop open the transformer and take out the coils. Set your multi meter to ohms and touch the contacts to either end of each of the coils (We got 2.2 ohms and 1500 phms ...

9

Hmm your experiment sounds like a good idea but I think it'll be much harder than you're imagining. The resistance of wires is very low. After all, they are designed to conduct! Check out this table. 30 gage wire has a resistance of $0.1\: \Omega/\mathrm{ft}$ which is well below what a typical multimeter can read. Also, because the resistance is so low, ...

6

Wire typically has very low resistance, so what you'll most likely end up measuring is the contact resistance.I.e., the resistance between your multimeter probes and the wire itself might have more resistance than your wire and overshadow it. My suggestion for the temperature dependent part would be to measure the resistance of the wire with it in boiling ...

3

That is the correct process, but you will want a multimeter that reads down into the 0.1 $\Omega$ range, something the Amazon-linked multimeter cannot do. Most home thermometers have a maximum of about 110 $^\circ$F, so if you plan on raising the temperature to larger than that, you'll want something different, something like this laser thermometer (Amazon ...

0

To state it simply, friction is the resistance to motion of an object within a system, in this case a ruler on a desk. As you suggest in your question the normal force to the surface is important to friction, the equation is: Coefficient of friction = force required to maintain constant velocity / normal force however turning the ruler on its side does ...

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You should be able to do it by jumping off a table onto a spring scale. Simply film the jump with a high speed camera and look for the shockwave that moves through your body as you are landing and note when it reaches your neck. At the same time note the distance the spring has moved (call it point x). Then note how much further the spring moved afterwards ...

1

A method that also applies to AC circuits is to move a magnet all the way through a loop connected to a volt meter and sum up all the measurement over time. (They should sum up to zero although the measurement errors may get in the way of a precise 0.)

7

If I understood your question correctly, then you want a simple experiment to demonstrate that magnetic monopoles cannot exist. The simplest way to explain this to a high schooler would be to actually break a small piece of magnet, and then make the student realize that the poles of the magnet haven't been 'split'; instead, both the pieces contain two poles. ...

0

The way I have heard it explained is not by the container but the water drops themselves. Statistically there is no way you can get a perfectly neutral water drop every single time. Eventually you will get a drop with a charge of 0.000000001 Farads. This tiny imbalance is enough to set the experiment in motion into a positive feedback system. You can think ...

2

This is similar, but not quite identical to Newton's cradle, with the difference being the heavy objects placed on the middle coins. To explain things, first consider the simpler case where there is no heavy object on top of the coins, and suppose the 5 nonmoving coins in "frame 1" are separated by a distance $L$. When two objects of mass $m$ and ...

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If the metal pan was cool then you would expect to see water droplets staying in the same place once any original movement had dissipated. You would have a combination of cohesive forces within each water droplet and adhesive forces between the water and metal surfaces. With the metal having a temperature well above the boiling point of water, the water ...

0

Just to add to the answer a DMM is not considered a good way to measure such a high impedance reading like skin conductivity. A typical Galvanic Response Sensor (GSR) has the ability to adjust filters/rates and is optimized for high impedance measurements to reduce the signal to noise ratio. DMM's will often pick up environmental noise on very high ...

2

It has nothing to do with any capacitance. It's all about skin resistance. The resistivity inside your body is much lower than that of the skin. As a result, your measurement is really showing you the sum of two resistances thru the skin. The main reason skin has higher resistance than the body internally is because the skin is dry. However, the skin ...

1

No, it's not diffraction. It's because you increase the depth of field by reducing the aperture. Basically, the more concentraded the light is, the better you see a defocused images. See this question: Why apperture affect depth of field in photography?

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