DAY 1: Current and Voltage/ Solderless Breadboard, Open-circuits and Shot-circuits

Current and Voltage 

The first question of the semester, what will happen when the switch is on? The answer is the bulbs stay the same because there is no different voltage between the wire of the switch, or the current does not pass through this wire.

the problem for the current definition: the time rate of change of charge. We find the function of charge in term of time and derivative it to get the current in term of time. 

Problem for the power and energy. From the graph i vs. t, we get the graph W vs. t and p vs.t through these formula p=v.i, and p=dw/dt => w= integral(p.dt)

From v vs.t and i vs. t graph, we get the p vs. t and w vs.t graph. we interpret the graph into the equation i(t) and v(t), then apply these formula to get the answer p=vi and w=integral(p.dt).

By applied the theory that the sum of the power in all elements is 0, we get the answer for the above problem

Lab: Solderless Breadboard, Open-circuits and Shot-circuits

Purpose:

This lab aims to give students the fundamental understanding of a breadboard where is the open-circuit and where is the short-circuit.

Procedure:

We use wires and digital multimeter as an Ohmmeter to check resistance in order to verify the circuits of a breadboard.  

1. Firstly, we measure the resistance between two holes in the same row. The DMM reads 0.4 Ohm , so it is a short-circuit. 

 

2. Secondly, we measure the resistance between two holes on opposite sides of the central channel of the breadboard. The DMM reads infinite Ohm , so it is an open-circuit.

 

3. Thirdly, we measure between two arbitrary holes in the breadboard. The DMM reads infinite Ohm, so it is an open-circuit.

 

4. Lastly, we measure between holes connected by a jumper wire. The DMM reads 3 Ohm, so it is a short-circuit.

We have the results in the white board. 1 and 4 are the short-circuits, while 2 and 3 are the open-circuits.

In conclusion

We learn about the basic property of the breadboard through this lab. We distinguish between the short circuit and open circuit. As the results showing, the connection inside a breadboard is the same like the following picture.