Alternating current L-R-C

inductance

Faradays law

Biot Savart

We begin with having a coil, a compass, and voltage source to explore the magnetic field produced by coils and its variance due to different currents. We derived an equation for the biot-savart law and used that to find an a equivalent for coils B(coil)=ulN/2R=B(earth)tan(theta)

We checked the currents with our ammeter in series in our circuit, again we used a potential source to observe the deflection of the compass needle for increasing currents.

We found the value of the magnetic field of the earth to 2.83*10^-5 T which accounted for by lining our compass up initially in the magnetic field so we could get good results from the magnetic field in the center of the coil that caused the needle deflection in our excel results and graph.

Motors

During this lab we experimented with an electric motor that utilized copper coils, magnetic fields, and current to cause torque on axle of the motor. The motor rotates 180 before  becoming an open circuit and letting the inertia of the armature close the circuit again and thus creating a torque.

We were tasked with creating our own motors using the ideas of coils, commutator's, and current. Next, we wrapped coils of copper for current to go through, sanded one end completely off and the other only partially to act as our commutator, then used a 3V source for our current.

This was our set up for our motor

 

 

 

 

We explored how  lines of current magnetic fields interacted. We found that they could be calculated using the principle of superposition, meaning equal and opposite currents magnetic fields would cancel out, while equal and same direction would be additive.

Magnetic Flux and Forces

During this lab we conducted experiments with magnetism, mainly focusing on magnetic flux and magnetic forces. We initially did a quick experiment with a bar magnet and compass, we used the compass tip as direction vectors that we plotted

 

Using metallic shavings we observed magnetic field lines similar to electric field lines but they are continuous. Sum B*da=0 gausses law for magnetic fields says that there are as many field lines coming in as leaving. They leave the north pole of the magnet bar and enter into the south pole. They have yet to observed as a monopole. 

 

 

Here we had a magnetic field produced by a permanent magnet with a current moving from right to left using the right hand rule. We expected to see a force move the copper pipe in our observation direction, which it did, thus confirming the formula for force in a magnetic field F=qv*B.

 

 

 

Here with our given information and the fact that  the pole had translational and rotational motion we had to utilize kinematics and the equation we found earlier in the day to find the value of the magnetic field 2.5 *10^-3 Telsa.

 

 

Next, we derived a proportionality between the magnetic field and the current present in the conductor.

 

Here we looked at torque and what factors contributed to a magnetic field causing moments. Using a rectangular square derived a relationship I that expressed torque as IAxB where we cross the factor Mu= IA with the mabgneticfield B.

Diode

During this lab we were introduced to diodes and transistors, the diode essentially allows current to pass through in one direction while blocking any current from entering from the opposite direction, the transistor can be utilized as a switch or even an amplifier, which is what we used it in for our circuit.

 

Using the breadboard we constructed the circuit that we were given in a diagram consisting of resistors, capacitors, diodes, and transistors .

 

 

 

We used that circuit as well as a phone and speaker to amplify the sound from the phone. We observed the two differing waves from the transistor and diode and the wave function generator.