Search Coil Experiment (measure magnetic field strength)

[@damandarin5415]

I have seen reasons to find the "constant"of proportionality" first, by withdrawing the search coil like you have done, but without any magnetic field. Why is this done, and how would it affect the calculation at the end (how would we factor it in)

[@PhysicsHQ]

Hi. That would probably enable you to calculate the signal associated with moving there search coil in the Earth’s magnetic field (and any other local fields). This would enable you to subtract background signal value from your results. So actual signal is reduced (depending on relative field orientations) from measured signal. Calculated field strength would be smaller (vice versa if actual signal is increased from measured).

[@defioctavia5516]

Hai I am from Indonesia I want to ask you Where can I buy the Neodymium magnet? Thank you so much

[@muhammadrehankhan3276]

Its good info thanq for that i have some question if you can please answer me related search coil

[@PhysicsHQ]

Sure. I’ll do what I can to answer your questions.

[@muhammadrehankhan3276]

Sir i want to know that i am making a high depth range gold detector for which i need a high depth level search coil with its ability to detect 20 feet down the earth or ground level the question is that what increases the depth range number of turns in search coil or copper wire with greater diameter

[@muhammadrehankhan3276]

And other question is that how much milli henry search coil can detect gold upto 5 feet

[@muhammadrehankhan3276]

Does magnetic field behaves silmilarly in mountains, rocks, and soft soil or it changes it behaviour according to the ground level

[@PhysicsHQ]

Hi. Could you clarify what you mean by “high depth range”? What sort of strength magnetic field are you trying to measure with your search coil? I think that I may not be best placed to answer the questions you have since they are about search coil design. I know how it works but not necessarily how to optimise its design. But I’ll try to help if I can.

[@TheZagros3000]

can this be used on general electronic devices?

[@PhysicsHQ]

In what way are you thinking of using it on general devices?

[@龙雨-i6o]

It looks like what is changed when you plucked out the coil is area A, not B? How come you ascribe the change in flux linkage to the change of B, rather than A? :3

[@PhysicsHQ]

You could look at it both ways. Either way A or B changes from its max value to zero. If you consider A then area of coil in flux is max and then goes to zero. Or B the coil goes from a region of max flux density to a region of zero flux density. But whichever method you use gives same result. Does that make sense?

[@龙雨-i6o]

@@PhysicsHQ Oh, I get it. Thanks!

[@zacharyirwin6980]

Can you tell me where you got your search coil?

[@PhysicsHQ]

Hi. Sorry I’m unable to do that. I’m in the fortunate position of inheriting a great deal of equipment from past teaching staff in my department. So I don’t know where these were bought from.

[@zacharyirwin6980]

@@PhysicsHQ Thank you for the response. I enjoyed your video.

[@muhammadrehankhan3276]

I subscribed your channel

[@believeornot12]

That method isn't accurate at all. It depends on how fast you can move and it is different from one person to another.

[@PhysicsHQ]

If time wasn’t measured it would indeed be inaccurate. But the picoscope measures and plots the signal against time. So in the analysis I used the measured time. It’s approximate insofar as the shape of the plot isn’t a perfect match, but it’s good enough. Also in the analysis I compare the B I obtained with the B obtained by use of the current balance method and got good agreement.

[@believeornot12]

@@PhysicsHQ The time you mentioned is the rise and fall time of the potential in the coil after being induced, which depends on the impedance and, perhaps, capacitance of the coil. The "how fast" I talked about is the velocity of the moving coil. The potential induced in the coil depends on how fast you move the coil. Think of a small generator. If you spin it slow, you get low voltage. If you spin it fast, you get higher voltage.