There is a link to do lab all info is there for lab. please show work clearly and do conclusion. The conclusion should include what was done in the lab. how the lab was accomplish. what is the lab...

I. Simulations

a) Access the Apps on Physics simulation:

Combination of Resistors

b) University of Colorado Boulders’ PhET:

Circuit Construction Kit: DC-Virtual Lab

II. Objectives

· Investigate the equivalent resistance of several combinations of resistors.

· Understand the voltage-current relationships for resistors in series.

· Understand the voltage-current relationships for resistors in parallel.

· Learn how to use a multimeter to measure current, voltage, and resistance.

III. Theory

A. Resistances in Series

Resistors are said to be connected in series when they are connected as in Fig. 1, such that there is the same current through each resistor. The potential drop across each resistor is not equal to the voltage of the battery or the power supply in the circuit, but the sum of the voltage across each resistor is.

Fig. 1

V = V₁ + V₂ = IR₁ + IR₂ = I (R₁ + R₂) = IR_S (1)

R_S = R₁ + R₂ (2)

R_S is called the equivalent resistance of the two resistors in series. The same reasoning can be applied to any number of resistors in series.

R_S = R₁ + R₂ + R₃ XXXXXXXXXX)

The total voltage across these resistors in series is:

V = V₁ + V₂ + V₃ + … (4)

B. Resistances in Parallel

Resistors are said to be connected in parallel when they are connected as in Fig. 2, such that the same voltage is applied across each resistor.

Fig. 2

The total current I from the power supply is the sum of I₁, the current through R₁, and I₂, the current through R₂.

(5)

where R_P is the equivalent resistance of the two resistors in parallel. The same reasoning can be applied to any number of resistors in parallel:

(6)

(7)

Part A: Equivalent Resistance

The purpose of this portion of the laboratory exercise is to calculate the equivalent resistance of resistors combined in series and in parallel.

Step 1. In this lab you will be considering combinations of resistors. In all cases,

R₁ = 120 Ω R₂ = 68 Ω R₃ = 100 Ω

Table 1 shows several arrangements of these three resistors. For each configuration, calculate the equivalent resistance of the combination. Show all your calculations.

Table 1. Equivalent Resistance

Step 2. Open the Apps on Physics Simulation Combinations of Resistors. Use the simulation to check your calculations for the first seven configurations on Table 1. Use the “Add resistor (in series)” and the “Add resistor (in parallel)” buttons to include multiple resistors into the circuit. To change the resistance of a resistor, click on the resistor and then type the desired value into the “Resistance” text box on right side panel, click enter. To check the equivalent resistance of multiple resistors, click and drag across the combination of resistors to highlight them all. The total resistance will be displayed at the top left corner of the orange highlighting box and at the bottom of the screen.

If in any case the equivalent resistance you calculated does not match the value given by the simulation, double check your calculations. Unfortunately, the simulation only supports a maximum of five resistors, so you will not be able to use it to check the last combination. Include screenshots of your circuit diagrams.

Part B: Resistors in Series

The purpose of this portion of the laboratory assignment is to calculate the current and voltage in a circuit composed of multiple resistors in series.

Step 1. Consider the circuit diagram shown below, which illustrates a combination of three resistors in series with a DC power supply.

Complete the first cell in Table 2 with the equivalent resistance of all three resistors. Use the same resistances for R₁, R₂, and R₃ as given in Part A above.

Step 2. Calculate the current in the circuit as well as the voltage drop across each of the resistors. Assume a source voltage of 12.0 V. Record your values in the “Theoretical Value” column of Table 2.

Step 3. Open the PhET simulation Circuit Construction Kit: DC – Virtual Lab and construct the circuit with the available tools. Click and drag each circuit element from the left side panel to the center of the screen. Click on each circuit element to adjust the resistances and the voltage to the correct values. On the control panel to the right, expand the “Wire Resistivity” panel and move the slider approximately one tenth of the way between tiny and lots.

Step 4. Use the voltmeter and ammeter to measure the voltage across each resistor and the current through the circuit. Remember that a voltmeter must be placed in parallel across the circuit element you are measuring

and an ammeter is placed in series with the resistors so that the same current that flows through the resistors also flows through the ammeter. You will have to break your circuit to correctly place the ammeter.

Record these values in the “Measured Value” column of Table 2 and calculate the percent error between your theoretical and measured values. Use the theoretical values as the actual or accepted values in this calculation. Show all your calculations and insert a screenshot of your complete circuit diagram including the meters.

Table 2. Resistors in Series

Part C: Resistors in Parallel

The purpose of this portion of the laboratory assignment is to calculate the current and voltage in a circuit composed of multiple resistors in parallel.

Step 1. Consider the circuit diagram shown below, which illustrates a combination of three resistors in parallel with a DC power supply.

In the lab, this circuit could be constructed with resistors, wire, and a DC power supply.

Complete the first cell in Table 3 with the equivalent resistance of all three resistors.

Step 2. Calculate the current in each branch of the circuit as well as the voltage drop across each of the resistors. Assume a source voltage of 12.0 V. Record your values in the “Theoretical Value” column of Table 3.

Step 3. In the PhET simulation, construct the circuit according to the circuit diagram or the photograph of the lab set-up. Ensure that the wire resistivity is once again set one tenth above tiny.

Use the ammeter and voltmeter to measure the current in each branch and the voltage across each resistor. Record these values in the “Measured Value” column of Table 3 and calculate the percent error between your theoretical and measured values. Show all your calculations and insert a screenshot of your complete circuit diagram including the meters.

Table 3. Resistors in Parallel

Part D. Resistors in Series-Parallel

The purpose of this portion of the laboratory assignment is to calculate the current and voltage in a circuit composed of resistors in a combination of series and parallel.

Step 1. Consider the circuit diagram shown below, which illustrates a combination of three resistors, an ammeter, and a DC power supply.

Complete the first cell in Table 4 with the equivalent resistance of all three resistors.

Step 2. Calculate the current in each branch of the circuit as well as the voltage drop across each of the resistors. Assume a source voltage of 12.0 V. Record your values in the “Theoretical Value” column of Table 4.

Step 3. In the PhET simulation, construct the circuit according to the circuit diagram. Use the ammeter and voltmeter to measure the current in each branch and the voltage across each resistor. Record these values in the “Measured Value” column of Table 4 and calculate the percent error between your theoretical and measured values. Show all your calculations and insert a screenshot of your complete circuit diagram including the meters.

Table 4. Resistors in Series-Parallel

IV.Queries

1.) Four identical light bulbs, each with a resistance of 20 Ω, are connected in series (circuit A) and placed across a potential of 12 V. a) What is the equivalent resistance of the circuit? b) What is the current in the circuit? c) If one of the bulbs burns out, the circuit is then open through that component, i.e., R is infinite. Would the remaining bulbs continue to burn? Explain. (Show all your work).

2.) In circuit B, the four identical light bulbs, each with a resistance of 20 Ω, are connected in parallel with the same battery of 12 V. (Show all your work).

a) What is the equivalent resistance of the circuit?

b) What is the total current drawn from the battery?

c) What is the current in one of the bulbs?

d) If one of the bulbs burns out, would the remaining bulbs continue to burn? If so,

would the remaining bulbs burn more brightly, burn more dimly, or stay the same? Explain.

3.) Compared to the individual bulbs in circuit A, the individual bulbs in circuit B are (show all work):

a) the same brightness.

b) 16 times brighter.

c) 4 times brighter.

d) ¼ as bright.

e) less than ¼ as bright.

CONCLUSION