11th grade Physics Portfolio (20 questions) on Electromagnetic Induction. Need 20 questions answered on attached portfolio.

electromagnetic_induction_laboratory_portfolio.docx

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Physics B Unit 3 Portfolio

Part 1 – Electromagnetism

Learning the content: You must watch this video prior to answering the questions below!

1. What are the two methods for creating magnetic fields?

_________________________________________________________ ______________________________________________________

2. One useful way to model magnetic field strength is to define a quantity called magnetic flux. Magnetic flux can be

described in three ways. What are the three different ways to describe magnetic flux?

A._________________________________________________________________________________________________

B._________________________________________________________________________________________________

C._________________________________________________________________________________________________

To the right is a picture of a bar magnet. Around the magnet, you can see magnetic

field lines drawn in.

3a. Field lines point from the ( NORTH POLE/ SOUTH POLE ) to the

( NORTH POLE / SOUTH POLE ).

3b. The magnetic field gets ( STRONGER / WEAKER ) the farther you get away from

the magnet.

3c. The magnetic field is ( STRONGER / WEAKER ) around the poles of the magnet.

4a. Look at the picture of the electromagnet to the right. What two things must be present to make an

electromagnet?

A.________________________________________________________

B.________________________________________________________

4b. In an electromagnet, the current moving through the conducting wire creates a magnetic field, which can be

strengthened by adding a metal core. ( TRUE / FALSE )

4c. If the wire is disconnected from the battery, what two things will happen?

_________________________________________________________ _________________________________________________________________

5. Look at the magnetic field lines for the electromagnet on the left and the bar magnet

on the right. How do they compare?

_______________________________________________________________________________________________

6. What are three uses of electromagnets? Try googling “uses of electromagnets.”

A._________________________________________________________

B._________________________________________________________

C._________________________________________________________

Applying the content: You must watch this video prior to answering the questions below!

7. Which is true about the behavior of magnets?

ANSWER ___________________________________

a. Both like and unlike poles can attract and repel each other depending on the surrounding materials.

b. Like poles attract each other, and unlike poles repel each other.

c. Like poles repel each other, and unlike poles attract each other.

d. None of the above are true.

8. The magnetic field of a bar magnet is shown in the figure to the right. Where is the magnet’s north pole?

a. midway between A and B

ANSWER ___________________________________

b. point B

c. point A

d. the magnet does not have a north pole

9. According to the right-hand rule, if a current-carrying wire is grasped in the right hand with the thumb in the

direction of the current, the four fingers will curl in the direction of the…

a. Magnetic field

b. Domain

ANSWER ___________________________________

c. South pole

d. North pole

10. To make an electromagnet stronger, it would be best to…

a. increase the current through the wire

ANSWER ___________________________________

b. decrease the current through the wire

c. increase the number of loops of wire

d. Both a. and c. are correct.

11. Choose the statement below that is FALSE about the magnetic field, B, around a current-carrying wire.

a. B is independent of the current in the wire.

ANSWER ___________________________________

b. B is inversely proportional to the distance from the wire.

c. The lines of B form concentric circles about the wire.

d. B is proportional to the current in the wire.

Part 2 – Electromagnetic Induction

Learning the content: You must watch this video prior to answering the questions below!

12a. What is electromagnetic induction?

_______________________________________________________________________________________________

12b. A charged particle passing through a magnetic field experiences a _______________________________________.

13a. A generator converts (ELECTRICAL / MECHANICAL) energy to (ELECTRICAL / MECHANICAL) energy.

Look at the picture of the generator below.

13b. The current is at a minimum at positions ___ and ___. At this point,

the plane of the loop is (parallel/perpendicular) to the magnetic field.

13c. The current is at a maximum at positions ___ and ___. At this point,

the plane of the loop is (parallel/perpendicular) to the magnetic field.

14. As the coil spins, the current is constantly changing ( DIRECTION /

MAGNITUDE / BOTH ).

15. What is effective current?

_______________________________________________________________________________________________

16. What does a transformer do?

_______________________________________________________________________________________________

Applying the content:

Need help with the math? You can look at the worked out sample problems on the last page of this portfolio.

17. An electron moves to the left with a velocity of 9.6 x 105 m/s and has a magnetic force of 2.6 x 10-15 N exerted on it.

What is the magnitude of the magnetic field? Assume the charge has a value of 1.60 x 10-19 C.

Givens:

Unknown:

Equation:

B=

Substitute:

Solve:

Fmagnetic

qv

Answer __________

18. The rms current output in a circuit is 4.67 A. What is the maximum current?

Givens:

Unknown:

Equation:

ΔIrms = (0.707)ΔImax

Answer __________

Substitute:

Solve:

19. The maximum current output of a 60 Ω circuit is 11 A. What is the rms voltage of the circuit?

Givens:

Unknown:

Equation:

Use this equation first: ΔVmax= ImaxR

Answer __________

Then, use this equation: ∆Vrms = (0.707) ΔVmax

Substitute:

Solve:

20. A step up transformer used in an automobile has a potential difference across the primary of 2200 V and a potential

difference across the secondary of 25 V. What is the ratio of the number of turns of wire on the primary to the number

of turns on the secondary?

Givens:

Unknown:

Equation:

∆V2 = ∆V1

N2

N1

Substitute:

Solve:

→→→→→Sample Worked Out Problems on Next Page →→→→→

Answer __________

Sample Worked Out Problems

1. An electron moves north at a velocity of 1.5 x 104 m/s and has a magnetic force of 2.2 x 10-14 N exerted on it. If

the magnetic field points upward, what is the magnitude of the magnetic field? Use 1.60 x 10-19 C for the magnitude

of the charge of an electron.

G: v = 1.5 x 104 m/s, Fmagnetic = 2.2 x 10-14 N, q = 1.60 x 10-19 C

U: B

Fmagnetic

E: B =

qv

S: B = ( 2.2 x 10-14 N ) / ( 1.60 x 10-19 C)( 1.5 x 104 m/s )

S: B = ( 2.2 x 10-14 N ) / ( 2.4 x 10-15 ) = 9.17 T

2. The maximum current supplied by a generator to a 35 Ω circuit is 8.2 A. What is the rms potential difference?

G (1): R = 35 Ω, ΔImax = 8.2 A

U (1): ΔVmax

E (1): ΔVmax = IR

S (1): ΔVmax = (8.2 A ) (35 Ω )

S (1): ΔVmax = 287 V

G (2): ΔV = 287 V

U (2): ΔVrms

E (2): ΔVrms = (0.707) ΔVmax

S (2): ΔVrms = ( 0.707 ) (287 V )

S (2): ΔVrms = 202.9 V

3. The rms current in an AC current is 16.9 A. Find the maximum current.

G: ΔIrms = 16.9 A

U: ΔImax

E: ΔIrms = ( 0.707 ) ΔImax

S: 16.9 A = ( 0.707 ) ΔImax

ΔImax = ( 16.9 A ) / ( 0.707 )

S: ΔImax = 23.9 A

4. A potential difference of 220 V across the primary of a step-down transformer provides a potential difference of

13.75 V across the secondary. What is the ratio of the number of turns of wire on the primary to the number of

turns on the secondary?

G: ΔV1 = 220 V, ΔV2 = 13.75 V

U: N1, N2

N2

E: ΔV2 = ΔV1 N1

S: Take the reciprocal → 1 / 0.0625 so we can flip the ratio

upside down because the problem asks for primary to

secondary or N1/N2.

S: 13.75 V = ( 220 V )

S:

13.75 𝑉

220 𝑉

=

N2

=

N1

0.0625

N2

N1

1

N2

= N1 =

0.0625

16 *NOTE: There is no unit because it’s a ratio.

Portfolio Resubmission/Correction Form

(To be completed after this assignment as been graded)

Want to raise the grade you got on this portfolio? Please see the directions and example on the next page

(or watch this recording) for help filling out the portfolio correction form. Incorrectly completed forms will

be sent back to you for resubmission.

Student Name ________________________________________

Portfolio: ___U3L7 __ Electromagnetism_________

Question

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

Missed?

Correct answer

Why is it correct?

Directions for Completing the Portfolio Resubmission Form

Portfolios can be corrected to help raise your grade. You can submit corrections using the resubmission

form above after you have turned in this portfolio and it has been graded. It is optional but highly

encouraged to submit corrections for portfolios.

Step 1: Check the grade comments for this assignment to see which questions you missed. Put a check mark or

X next to the question number(s) that you missed.

Step 2: Fill in the correct answer for the questions you missed. You will not receive any credit for the

correction if you do not complete the “Why is it correct” column.

Step 3: Webmail the completed resubmission form to your teacher.

EXAMPLE:

Student Name ___Harry Potter____________________________

Portfolio: U3L3 – Can you feel the Power ____________________

Question

Missed?

Correct answer

Why is it correct?

1

x

Force, displacement,

direction

That is the definition of work. I didn’t watch the

recording. I watched it and it helped me SOOOO

much! 🙂

2

….

17

x

D

There is no work being done on the person being

carried across the floor b/c the direction of the

displacement and the force are not in the same

direction, which is required for work to be done.

….

19

x

454.2 J

G: h = .45m, m = 103kg, g =

9.8m/s

U: PE

E: GPE = mgh

S: GPE = (.45)(103)(9.8)

S: GPE = 454.2 J

If you have any question on how to fill this out, please call! 🙂

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