Physics A and B (One Credit)

The goal of physics is to describe the physical world using a small number of basic assumptions, concepts, and equations. In this course, emphasis is placed on relating physics to the everyday world.

This course will explore the concepts involved with motion in one and two dimensions, forces, work and energy, momentum and collisions, circular motion, and gravitation. Throughout the course students will learn to recognize the importance of the laws of thermodynamics. Students will study the characteristics of waves and describe the behavior of waves, with emphasis on light and sound. Students will also learn about the relationship between electricity and magnetism. Finally, students will gain a basic understanding of atomic physics. This course is designed to enhance the understanding and appreciation of concepts that are fundamental to the study of physics.

Students are required to participate in virtual laboratory investigations throughout this class that are within the course content and online. Labs are an important part of the scientific process, and understanding the scientific process is one of the most important parts of this class. Students will gain a detailed understanding of the scientific process and lab procedures by performing labs related to physics concepts.

Lab Assignment: Free-Fall Acceleration Laboratory:

Introduction

This lab will demonstrate the principles behind free-fall acceleration. Any object that is thrown or dropped in the presence of gravity experiences a constant acceleration. This acceleration is called free-fall acceleration or acceleration due to gravity.

Objectives:

1. Analyze motion in terms of the change in distance during a given period of time.

2. Summarize the relationships between distance and time for moving objects.

3. Interpret graphs relating distance and time for moving objects.

Lab Assignment: Projectile Motion Laboratory:

Introduction

This lab will demonstrate the principles behind projectile motion. An object that has constant horizontal velocity and constant vertical acceleration is a projectile.

Objectives

1. Implement experimental procedures to understand projectile motion.

2. Generate data about the horizontal and vertical motion of a projectile.

3. Compare the motion of projectiles launched at different heights and initial velocities.

4. Interpret and evaluate graphs of projectile motion.

Lab Assignment: Forces and Friction Laboratory

Introduction

This lab will demonstrate the principles behind forces and friction. Friction is a force that works in the opposite direction to an applied force. Static friction is the friction that occurs when an object is not moving. Kinetic friction is the friction that occurs once an object starts moving.

Objectives:

1. Compare the coefficients of static and kinetic friction for the wooden and glass surface.

2. The value of the static friction force and kinetic friction force increases with the weight (Normal force) of the blocks, but the coefficient of static and kinetic friction remains the same for the given surface.

3. Evaluate the relationships between mass, acceleration, and force.

Lab Assignment: Conservation of Mechanical Energy Laboratory: Introduction

This lab will demonstrate the principles behind the law of conservation of mechanical energy. Mechanical energy is never created nor destroyed, but it can be converted from one form to another. In this lab, you will study what happens when mechanical energy is converted between elastic potential energy and gravitational potential energy using a mass on a spring.

Objectives:

1. Determine the spring constant of a spring.

2. Calculate elastic potential energy.

3. Calculate gravitational potential energy.

4. Evaluate whether mechanical energy is conserved in an oscillating spring.

Lab Assignment: Momentum Laboratory: Introduction

This lab demonstrates conservation of momentum. Momentum is the product of the mass and velocity of a moving object. Studying momentum helps physicists understand the relationship between the motions of two interacting objects.

Objectives:

1. Generate data for both elastic and inelastic collisions

2. Calculate the momentum of each object in different collisions

3. Evaluate data to verify the law of conservation of momentum.

Lab Assignment: Machines and Efficiency Laboratory: Introduction

This lab demonstrates the principles of mechanical advantage and efficiency with regard to simple machines. Mechanical advantage is the ratio of output force to input force. Efficiency is the ratio of work output to work input. Studying mechanical advantage and efficiency helps physicists design machines that are most effective at doing their job.

Objectives:

1. Measure the work input and output of various machines.

2. Calculate the efficiency of each machine.

3. Compare machines based on their efficiencies, and determine what factors affect efficiency.

Lab Assignment: Thermal Equilibrium Laboratory: Introduction

In this lab, you will place two objects with different temperatures next to each other. You will observe how different materials and different masses affect the rate of heat flow. Thermal equilibrium occurs as a result of the heat energy transfer between two objects with different temperatures that are in physical contact with each other. Heat is defined as a transfer of energy due to difference in temperatures. With this concept in mind, we are going to apply conservation of energy in an ideal system and assume no losses for this lab. In this lab, you will study how thermal equilibrium occurs when two objects of different temperatures are placed in physical contact with each other.

Objectives:

1. Generate data on the time required to achieve thermal equilibrium between the two objects.

2. Evaluate the different equilibrium temperatures of the objects based on composition, mass and time.

Lab Assignment: Piston Laboratory: Introduction

This lab will demonstrate some of the principles behind the work done on or by a gas. As a gas changes volume, work is done. In this lab, you will study how work is done by a gas in a piston.

Objectives:

1. Generate data on how changes in the volume of a gas affect the behavior of a piston.

2. Evaluate data generated by experimentation on the piston in terms of work and energy.

Lab Assignment: Simple Harmonic Motion Laboratory: Introduction

This lab will demonstrate the principles of simple harmonic motion. It is an oscillating motion in which the restoring force is proportional to the displacement. In this lab, you will study the simple harmonic motion using a pendulum.

Objectives:

1. Construct simple pendulums, and find their periods.

2. Generate values for ag, the free fall acceleration.

3. Evaluate the relationships between length and period for different pendulums.

Lab Assignment: Wave Laboratory: Introduction

This lab will demonstrate some of the principles of waves. A mechanical wave is the motion of a disturbance to a medium. In this lab, you will study waves through a virtual string of beads.

Objectives:

1. Compare the behavior of a wave on a string with changes in frequency and amplitude.

2. Evaluate the relationships between frequency, amplitude, and wavelength in a wave.

Lab Assignment: Sound Laboratory: Introduction

Now is the time for the laboratory activity for ‘sound’. This lab will demonstrate some of the principles of sound. Sound waves create regions of air that are compressed and rarefied. In this lab, you will study the speed at which these sound waves travel.

Objectives:

1. Develop two methods to measure the speed of sound in air.

2. Evaluate the relationship between frequency and the speed of sound.

Lab Assignment: Converging Lenses Laboratory: Introduction

This lab will demonstrate some of the principles of converging lenses. Converging lenses can produce both real and virtual images. In this lab, you will study image formation using converging lenses.

Objective:

1. Evaluate the relationships between the positions of the lens and the object, and the position and the size of the image.

Lab Assignment: Electrostatics Laboratory: Introduction

This lab will demonstrate some of the principles of electrostatics. When two different materials are rubbed together, electric charges accumulate on both objects. In this lab, you will study how charges accumulate on objects and distinguish between types of charges.

Objectives:

1. Evaluate the properties of static electricity.

2. Categorize different types of electric charges.

Lab Assignment: Charges and Fields Laboratory: Introduction

This lab will demonstrate some basic ideas of the variation of electric field strength with the distance of the charge, variation of electric field strength for different charges and the variation of equipotential at a distance due to different charges. In this lab, you will study how electric potential and electric field strength are related to each other.

Objectives:

1. Determine the effects of changing distance on the electric field strength produced by the charge and the effects of changing charge on the electric field strength at a particular distance.

2. Determine the effects of changing the charges on the value of the equipotential.

3. Appraise the relationships between electric field and electric potential for any charge.

Lab Assignment: Ohm’s Law Laboratory: Introduction

This lab will verify and demonstrate Ohm’s Law. In this lab, you will study how current, voltage, and resistance are all related to each other and also determine the unknown resistance.

Objectives:

1. Verify Ohm’s Law, .

2. Determine the value of unknown resistance.

Lab Assignment: Ohm’s Law And Factors Affecting the Resistance Laboratory : Introduction

This lab will demonstrate how various factors affect the resistance of the material of the coil. In this lab, you will study how different factors such as the length, area, and the temperature would affect resistance individually. You will also determine the temperature coefficient of resistance of the material.

Objectives:

1. To understand the fact that resistance of the coil increases with the increase of the length.

2. To understand the fact that resistance of the coil decreases with the increase of area of cross–section.

3. To determine the value of temperature coefficient of resistance ‘α’ of the material of the coil.

Lab Assignment: Resistors in Series and in Parallel Laboratory: Introduction

This lab will demonstrate some of the principles of electric circuits. In this lab, you will study resistors in series and in parallel circuits.

Objectives:

1. Measure current in and potential difference across resistors in series and in parallel.

2. Determine the unknown resistances of two resistors.

3. Compare equivalent resistances.

4. Evaluate the relationships between potential difference, current, and resistance.

Lab Assignment: Magnetic Field of a Solenoid Laboratory: Introduction

This lab will demonstrate some of the principles of magnetic fields. When a current runs through a wire, a magnetic field is generated. In this lab, you will study the relationship between the magnitude of the magnetic field and the number of loops in a solenoid.

Objectives:

1. Explore the magnitude of the magnetic fields of solenoids of varying numbers of loops.

2. Evaluate the relationship between the magnitude of the magnetic field of a conducting wire and the distance from a solenoid.

PHYSICS A Virtual Labs

Lab 1 Assignment: Free-Fall Acceleration Laboratory: Description

Developing Hypothesis:

In this lab you, will investigate free-fall acceleration on the Earth, the Moon, and Mars. You will measure displacement of an object in free-fall and then calculate its acceleration.

Hypothesize what you think the results of this experiment will be. Will the acceleration you measure be the same in all three environments? How will your measurements compare to accepted values of free-fall acceleration?

Enter answer:

Objectives :

1. Analyze the free-fall acceleration on the Earth, the Moon and Mars – here they analyze motion in terms of the change in distance during a given period of time.

2. After graphing the Acceleration, Position and the velocity vs.Time for the different planets, Earth, Moon and Mars, the students will analyze and summarize the relationships between distance and time for moving objects.

The students will measure the displacement of an object in free fall and then calculate its acceleration. In this virtual lab, they are provided with a timer, a ruler, an object that can be put into free fall and a button that can change the location of the lab from the Earth to the Moon or to Mars. The timer will be used to determine the average velocity and the average acceleration of a falling body in different locations.

Main Procedures of the lab :

. This virtual laboratory is found at the website: http://jersey.uoregon.edu/AverageVelocity/index.html

. Prepare the spreadsheet to record data. Three tables will be needed – one for Earth, one for Moon and one for Mars. The student is given the data for each object for the time in seconds.

• On the Earth table, label each column 0.0, 0.2, 0.4, 0.6, 0.8, and 1.

• On the Moon table, label each column 0.0, 0.4, 0.8, 1.2, 1.6, and 2.0.

On the Mars table, label each column 0.0, 0.3, 0.6, 0.9, 1.2, and 1.5

. The relationship between displacement and the time for dropping the ball is found by setting and re-setting the gravity button a few times.

. The readings for Moon and Mars are found by choosing the respective buttons and repeating the above steps.

. After the above steps the average velocity is calculated. Then using this, the average acceleration is calculated.

. The absolute error and the relative error of the results are determined after the above steps using the formula given.

Displacement of a Falling Object

4. Estimate how far you think the ball will fall in 0.2 s. Place the red marker in this location on the ruler. Press drop. Adjust the red marker until you exactly determine the displacement of the ball in 0.2 s. Repeat this procedure for each column in the data table for Earth.

5. Change the gravity setting to the Moon. Repeat the procedure until you have collected displacement measurements for each of the times in the Moon data table.

6. Repeat step 4 choosing the gravity on Mars. Record your data in the Mars data table.

Analysis

1. Organizing Data: For each of the environments, calculate the average velocity. Divide the distance between two time points by the change in time. You might want to create new rows in your spreadsheet with these values. Notice that you will only have five values of average velocity in each location. The calculations and data in red have been done for you. You must calculate and enter the remaining data.

Average velocity = (change in distance)/(change in time)

Average velocity = (d2 – d1)/ (t2 – t1)

Average velocity = (0.2 – 0)/ (0.2 – 0) = 0.2/0.2 = 1 m/s

Average velocity = (d2 – d1)/ (t2 – t1)

Average velocity = (0.83 – 0.2)/ (0.4 – 0.2) = 0.63/0.2 = 3.15 m/s

Average acceleration = (change in velocity)/(change in time)

Average acceleration = (v2 – v1)/ (t2 – t1)

Average acceleration = (3.15 – 1)/ (0.4 – 0.2) = 2.15/0.2 = 10.75 m/s2

Time (seconds) 0 0.2 0.4 0.6 0.8 1.0

Distance (meters) 0 0.2 0.83

Average velocity (m/s) 1 3.15

Average acceleration 10.75

2. Organizing Data: Using the results from item 1, calculate the average acceleration. Find the change in speed between the first and second time points and the second and third time points and divide this by the change in time. You may want to add another row to your data tables for these calculations. Notice that you will only have four values of average acceleration.

3. Constructing Graphs: Use your data to plot the following graphs for each environment. On each graph, label the axes and indicate the trial number.

a. Position versus time

b. Velocity versus time

c. Acceleration versus time

4. Organizing Data: Use the values for the average acceleration for all four trials to find the average value.

5. Evaluating Results: Use the accepted value for the free-fall acceleration on Earth given in the text and the average of your results from item 4.

a. Determine the absolute error of your results using the equation:

relative error = |experimental - accepted|

b. Determine the relative error of your results using the following equation:

relative error = (experimental - accepted) / accepted

Conclusions

1. Making Predictions: Based on your results, how do the average accelerations on Earth, the Moon, and Mars relate to each other? How did this result compare to your hypothesis?

2. Analyzing Graphs: Calculate the slope of each velocity-time graph you made.

3. Evaluating Results: Find the average value of the slope of the velocity-time graphs. What is the relationship between this value and the values you found for the average acceleration in each location?

4. Analyzing Error: You used a virtual simulation that was programmed with the gravity value on Earth. Why would you still expect to find absolute error and relative error in your measurements of acceleration? How might you do the experiment so that your value of acceleration on Earth would be closer to the accepted value? How did this outcome compare to your hypothesis?

Lab 2 Assignment: Machines and Efficiency Laboratory

In this lab you will demonstrate the principles of mechanical advantage and efficiency with regard to simple machines.

You will first design an experiment you could construct, that might measure the mechanical advantage and efficiency of a simple machine and then you will answer questions based on that experiment.

Developing Hypothesis:

In this experiment, you will study and compare the mechanical advantage and efficiency of a pulley with those of an inclined plane.

Create hypotheses of what you think the results of this experiment will be.

• Which machine will have the most mechanical advantage?

• Which machine will be the most efficient?

Defend your hypotheses with your knowledge of forces and work. Your answers will be part of your lab write-up that you submit to your teacher.

Objectives:

1. Measure the work input and output of various machines.

2. Calculate the efficiency of each machine.

3. Compare machines based on their efficiencies, and determine what factors affect efficiency.

To view the items that need to be included in your lab write-up along with a grading rubric, please refer to the Guidelines for the Laboratory section.

Procedure

Preparation

1. Read the entire lab procedure and plan the steps you will take.

2. You will need to use two different websites for this virtual lab. The inclined plane is found at http://phet.colorado.edu/web-pages/simulations-base.html. Click on the Work, Energy, and Power link on the left. Then, click on the lab called The Ramp. It will download and open on your computer.

The pulley system is found at http://www.walter-fendt.de/ph14e/pulleysystem.htm.

3. Prepare two data tables in your spreadsheet program. Table 1 is for the inclined plane lab. Label columns: Trial, Object, Mass (kg), Incline Angle (degrees), Applied Force (N), Work Applied (J), Distance (m). Table 2 is for the pulley lab. Label columns Trial, Number of pulleys, Mass (kg), Mass of pulleys (kg), and Necessary Force (N). The example below shows how to set up your data tables.

Table 1 - Inclined Plane

Trial Object Mass (kg) θ Force Applied (N) Work Applied (J) Distance (m)

4.

Table 2 - Pulley

Trial Number of pulleys Load Weight (N) Pulley Weight (N) Necessary Force (N) string (cm) load (cm)

Analysis

Inclined Plane

1. Organizing Data: For each trial make the following calculations. You should add columns to your spreadsheet for the calculations.

a. the change in height of the object, which is the distance along the ramp times the sine of the ramp angle

b. the output force, which is the same as the weight of the object being raised

c. the output work, which is the product of the output force and the change in height of the object

d. the mechanical advantage, which is equal to the ratio of the output force to the input force (or the applied force)

e. the efficiency, which is equal to the ratio of the work output to the work input. (Remember that W = F • âˆ†d)

2. Analyzing Results: In which trial did the machine perform the most work? In which trial did it perform the least work?

3. Analyzing Results: Under what conditions was the mechanical advantage the greatest? When was it the least?

4. Analyzing Results: How did changing the mass of the object change the mechanical advantage of the machine?

Pulley

5. Organizing Data: Make the following calculations for each trial. You should add columns to your spreadsheet for the calculations:

a. the work input, which is equal to the product of the necessary force and the change in height of the string

b. the work output, which is equal to the sum of the weights of the pulleys and the load multiplied by the change in height of the load

c. the mechanical advantage, which is equal to the ratio of the output force (the sum of the weights of the pulleys and the load) to the input force (or the necessary force)

d. the efficiency, which is equal to the ratio of work input to work output

6. Analyzing Results: In which trial, did the machine perform the most work? In which trial, did it perform the least work?

7. Analyzing Results: Under what conditions was the mechanical advantage the greatest? When was it the least?

Conclusions

1. Drawing Conclusions: Based on your calculations, which machine has the most mechanical advantage: a pulley system or an inclined plane?

2. Drawing Conclusions: Based on your calculations, is an inclined plane or a pulley system more efficient? Explain your answer.

3. Evaluating Methods: How would performing this experiment in a hands-on laboratory affect your calculation of efficiency? What differences you might expect doing these experiments with real-life machines that you are neglecting in a virtual setting?

4. Evaluating Hypotheses: How did your hypothesis compare to the results of your experiments?

The lab report that you submit to your teacher should include:

1. A document file (RTF) containing:

• Your experimental design idea and answers to the initial questions

• Your hypothesis about this experiment supported with physics concepts

• Conclusions from this experiment

2. Copy the following spreadsheet information into your document:

• Data Tables 1 and 2

• All of the tables you produced to do your calculations of mechanical advantage and efficiency for the data collected in Tables 1 and 2

Reminder: Be sure to submit your assignment at this time. Refer to the Guidelines for the Laboratory section for directions on how to submit your assignment to your instructor.

PHYSICS B Virtual Labs

Lab 1 Assignment: Ohm’s Law And Factors Affecting the Resistance Laboratory

In this lab you will demonstrate how various factors affect the resistance of the material of the coil. You will study how different factors such as the length, area, and the temperature would affect resistance individually. You will also determine the temperature coefficient of resistance of the material.

Developing a Hypothesis:

In this experiment, you will find the change of resistance values of the coil of different lengths, different area of cross-section, and the temperature change for the given coil. The resistance value can be calculated using the Ohm’s law in each of the trials of the experiment.

Create hypotheses of what you think the results of this experiment will be. Examples below :

• For the given cell, the resistance of the coil increases with increase of length. So resistance is directly proportional to length.

• For the given cell, the resistance of the coil decreases with the increase of area of cross-section. So resistance is inversely proportional to area.

• For the given cell, the resistance of the coil increases with increase of temperature.

Defend your hypotheses with your knowledge of current and resistors. Your answers will be part of your lab write-up that you submit to your teacher.

Objectives:

1. To understand the fact that resistance of the coil increases with the increase of the length.

2. To understand the fact that resistance of the coil decreases with the increase of area of cross–section.

3. To determine the value of temperature coefficient of resistance ‘α’ of the material of the coil.

To view the items that need to be included in your lab write-up along with a grading rubric, please refer to the Guidelines for the Laboratory section.

Procedure

1. Read the entire lab procedure and plan the steps you will take.

2. You can find the virtual lab by clicking here. The lab report will contain the data tables, etc. mentioned in the Procedures below. Click on the link here to access the lab report: http://aventalearning.com/content168staging/2008Physics/SectionB/labs/oh...

3. Prepare a data table-I for experiment –I using your spreadsheet program. Label the 6 columns as Trail No., Temperature, Length of the coil, Voltmeter reading, Ammeter reading, and resistance. You will need enough rows for five trials.

4. Prepare a data table –II for experiment –II using your spreadsheet program. Label the 6 columns as Trail No,. Temperature, area of the coil, Voltmeter reading, Ammeter reading, and resistance. You will need enough rows for five trials.

5. Prepare a data table-III for experiment –III using your spreadsheet program. Label the 5 columns as Trail No., Temperature, Voltmeter reading, Ammeter reading and resistance. You will need enough rows for five trials.

6. The experimental setup for the experiment –I consists of 3 dry cells of emf 6V, 9V and 12V, 5 coils of 5 different lengths but of same area of cross-section, a thermometer, a voltmeter and an ammeter. Ammeter should be connected in series to the coil and voltmeter should be connected in parallel across the cell as explained in the demo. Play the lab a little while to become familiar with how it works.

7. First connect the voltmeter across the cell and it will show the value of the emf of the cell, but this is not the voltmeter reading. Then connect the positive terminal of the ammeter to the positive pole of the cell and its negative terminal to the Q end of the coil. The other end P of the coil should be connected to the negative terminal of the cell as shown in the demo. The thermometer is kept in contact with the coil to measure its temperature. Once the circuit is closed, record the voltmeter and ammeter reading.

8. Repeat the step 7 for different trials by changing the length of the coil. Record the voltmeter and ammeter reading for each trial. Record the values of voltmeter and ammeter reading in the respective column in the data table-I.

9. The experimental setup for the experiment –II consists of 3 dry cells of emf 6V, 9V and 12V, 5 coils of 5 different cross sectional areas but of same length, a thermometer, a voltmeter and an ammeter. Ammeter should be connected in series to the coil and voltmeter should be connected in parallel across the cell, as explained in the demo.

10. Repeat the step – 7 for different trials by changing the area of the coil. Record the voltmeter and ammeter reading for each trial in the data table-II.

11. The experimental setup for the experiment –III consists of 3 dry cells of emf 6V, 9V and 12V, coil of 10 m length and cross-sectional area 0.01 m2, a thermometer, a burner, a voltmeter and an ammeter. Ammeter should be connected in series to the coil and voltmeter should be connected in parallel across the cell as explained in the demo.

12. First connect the voltmeter across the cell and it will show the value of the emf of the cell, but this is not the voltmeter reading. Then connect the positive terminal of the ammeter to the positive pole of the cell and its negative terminal to the Q end of the coil. The other end P of the coil should be connected to the negative terminal of the cell. The burner is dragged and kept below the coil but not switched ON. The thermometer is kept in contact with the coil to measure its temperature. Once the circuit is closed, record the voltmeter and ammeter reading.

13. Now switch on the burner, and note down the value of voltmeter reading and ammeter reading for increase of every 50° of temperature. You can go up to 5 trials and record the values in the data table-III.

Analysis

1. Organizing Data: Note down the values of voltmeter reading and ammeter reading for the coils of different length in the experiment – I. Calculate the value of resistance of the coil for each length using the formula .

2. Organizing Data: Note down the values of voltmeter reading and ammeter reading for the coils of different cross-sectional area in the experiment – II. Calculate the value of resistance of the coil for each cross-sectional area using the formula .

3. Organizing Data: Note down the values of voltmeter reading and ammeter reading for the given coil for different values of temperature in the data table –III of the experiment III, and calculate the value of resistance for each value of temperature using the formula .

4. Calculating Temperature Coefficient of Resistance (α): Use the following formula to calculate the temperature coefficient of resistance (α) for the experiment III.

In the above formula, R2 and R1 are the resistances at temperatures T2 and T1 respectively. is the difference in temperature between T2 and T1.

Repeat this calculation for different combinations of temperatures and find the mean for .

Conclusions

1. Drawing Conclusions: According to the results from your experiments, answer the following questions:

• What happens to the resistance of the coil if its length is increased?

• What happens to the resistance of the coil if its area is increased?

• What happens to the resistance of the coil if its temperature is increased?

2. Making Predictions: A wire of length L m has 2Ω resistance. It is stretched twice its original length and its area becomes half of its original area. What is its new resistance?

3. Interpretation Graphs: What is the resistance of the coil A at 600 K if its resistance at 300 K is 50 Ω? (Assume the temperature coefficient of resistance of the coil is .007/ °C)

The lab report that you submit to your teacher should include:

1. A document file (RTF) containing:

• Your experimental design idea and answers to the initial questions

• Your hypothesis about this experiment supported with physics concepts

• Your observation table from your experiments

• Answers to Conclusions from this experiment

• Answers to the post lab questions

2. Copy the following spreadsheet information into your document:

• Your data tables I,II and III from your experiments along with calculations from the Analysis section

• The calculated value of the temperature coefficient of resistance in the Analysis section

Refer to the Guidelines for the Laboratory section for directions on how to submit your assignment to your instructor.

Lab 2 Assignment: Magnetic Field of a Solenoid Laboratory:

In this lab you will demonstrate some of the principles of magnetic fields. When a current runs through a wire, a magnetic field is generated. You will study the relationship between the magnitude of the magnetic field and the number of loops in a solenoid.

You will first design an experiment you could construct that might measure the magnetic field of a solenoid. And then, write down your answers; this information will be part of your lab write-up that you submit to your teacher.

Developing a Hypothesis:

When a current-carrying wire forms a loop, it is called a solenoid. The number of loops of wire influences the magnitude of the magnetic field the solenoid produces.

Create hypotheses of what you think the results of this experiment will be.

• What is the relationship between the number of loops of wire and the magnitude of the magnetic field?

• What is the relationship between the magnitude of the magnetic field in a solenoid and the distance from the solenoid?

Defend your hypotheses with your knowledge of charges, conductors and insulators. Your answers will be part of your lab write-up that you submit to your teacher.

Objectives:

1. Explore the magnitude of the magnetic fields of solenoids of varying numbers of loops.

2. Evaluate the relationship between the magnitude of the magnetic field of a conducting wire and the distance from a solenoid.

To view the items that need to be included in your lab write-up along with a grading rubric, please refer to the Guidelines for the Laboratory section.

Procedure

1. Read the entire lab procedure and plan the steps you will take.

2. You can find the virtual lab by clicking here. On the left side of the screen scroll down and click on the Electricity, Magnets & Circuits link. Click on the virtual lab called “Faraday’s Electromagnetic Lab.” It should automatically download and open on your computer.

3. Click on the tab that says Electromagnet. The experimental set up will look like the graphic below.

Click on the radio button that says Show Field Meter. This will make a meter that detects the magnetic field appear. The X in a circle at the top of the meter is the location where the measurement is made. For the purposes of this lab, you will use the magnitude of the magnetic field, B. Move the meter to a location to the left of the electromagnet, centered on the loop and just below the left edge of the battery. Move the compass that is to the left of the battery so that it is also centered on the magnetic field meter. Do not move either until you have completely filled in your first Data Table.

4. Prepare two Data Tables using your spreadsheet program. In the first row label the columns: Turns, Compass Direction, Current Direction, and Strength of Magnetic Field. In the first column label the rows 1, 1, 2, 2, 3, 3, 4, 4.

5. Move the Voltage on the battery all the way to the right. Notice the compass direction and the direction of the movement of the light blue balls that represent electrons in the coil. Record this in your first Data Table. Decrease the number of loops of the current to 1 and record the value of B.

6. Reverse the direction of the current by moving the slider on the battery all the way to the left. Record all the relevant information in your Data Table.

7. Repeat the procedures in Steps 5 and 6 for 2 coils, 3 coils and 4 coils.

8. Move the magnetic field meter directly to the left of its current location an inch or two. Try not to move it vertically.

9. Repeat Steps 5 through 7 with the magnetic field meter in this new location, which is farther from the electromagnet. Record your measurements and observations in your second Data Table.

Analysis

1. Constructing Graphs: Using a graphing program, create a graph of the number of turns versus magnitude of the magnetic field for the two different locations of the magnetic field meter.

Conclusions

1. Drawing Conclusions: What is the relationship between the magnitude of the magnetic field and the number of turns? Explain.

2. Drawing Conclusions: What is the relationship between the magnitude of the magnetic field and the distance from the solenoid? Explain.

3. Drawing Conclusions: What is the relationship between the direction of current in the wire and the direction of the magnetic field? Explain.

The lab report that you submit to your teacher should include:

1. A document file (RTF) containing:

• Your experimental design idea and answers to the initial questions

• Your hypothesis about this experiment supported with physics concepts

• Your Data Table from your experiments

• Answers to the Conclusions from this experiment

2. Copy the following spreadsheet information into your document:

• Your Data Tables from your experiments

• Your graph or graphs from the Analysis section

3. You can use the following data table for the lab report :

Turns Compass Direction Current Direction Strength of Magnetic Field

Your Graphs should be similar to examples below :

Refer to the Guidelines for the Laboratory section for directions on how to submit your assignment to your instructor.

### Requested competency code:

- Lab Science

Labs are virtual, need to have more physical labs than virtual to meet ABOR policy requirements.