Download 3rd 9 weeks test PEOPLE and SYMBOLS practice

Name ____________________________________________________ period _________
3rd 9 weeks test PEOPLE and SYMBOLS practice
Instructions: Work in groups following Quiz-Quiz-Trade activity
Date: Monday 2/25/13
Write what each symbol means, including the unit
Symbol
1.
F electric
2. k
3. q
4. r
5. E
6. RTotal
7. 1/RTotal
8. P
9. V
10. I
11. R
12. Q
13. N
14. e
15. Fmagnetic
16. v
17. B
18. ℓ
Meaning
unit
Write the name of the person who contributed the idea/concept/ theory
19.Whose law for electric charges relates type, size, and distance between the charges to the
force on each charge? _______________________
20.Who is the scientist that created an experiment using oil drops placed within a capacitor
field to show that all charges are a multiple of 1.6 x 1019 Coulomb? (ex. Electron and
proton charges) _______________________
21.Which of the following scientists supported the idea of two kinds of charge and invented
lightning rods? _______________________
22.Who determined the planetary model of an atom that has electrons orbiting around a
heavy, positively charged nucleus. _______________________
23.Developed 4 equations describing electromagnetism, including the speed of light
_______________________
24.electromagnetic induction—that an electric current created a magnetic field, and that a
moving magnetic source could induce a current. _______________________
25.formulated the law of magnetic induction quantitatively _______________________
26.Measured the speed of light (c= 3.0x108m/s) _______________________
27.predicted that light and other waves (radar, X-rays, etc.) are electromagnetic waves, and
he also described their properties. _______________________
28.the speed of light is the same regardless of your own motion; result is the heart of
Einstein’s Special Theory of Relativity _______________________
29.Changing electric fields (new concept in these equations) induce changing magnetic
fields _______________________
30.Developed the theory of induction _______________________
31.Motors, generators, and transformers _______________________
Name ____________________________________________________ period _________
3rd 9 weeks test CALCULATION practice
Part 1: IWB
Instructions: Show all formulas and work in the space provided.
Complete IWB activity using questions below. Fill-in with numbers from IWB and solve. Show
your answer on the marker board provided.
Date: Tuesday 2/26/13
Formulas
F electric= k(q1q2)/r2
E=Fq
RTotal= R1 + R2+ R3…
1/RTotal= 1/R1 + 1/R2+ 1/R3…
P=VI
I=V/R
Q=Ne
Fmagnetic =qvB
Fmagnetic= BIℓ
Constants and conversions
1m= 100cm
1m= 1000mm
Charge on electron= -1.6x10-19C
Charge on Proton= +1.6x10-19C
kc= Coulomb’s constant= 8.99x109 N∙m2/C2
1. Two charged spheres are 20 cm apart and exert an attractive force of 8 x 109N on each
other. What will be the force of attraction when the spheres are moved to 10 cm apart?
2. A positive 6.0 x 10-9 C charge experiences a force of 1.8 x 10-5 N to the right. What is
the electric field at the location of that charge from other charges?
3. A piece of fur is rubbed against a plastic rod. The resulting charge on the rod is -18
microCoulombs. What charge does the fur acquire?
4. How much charge (Q) could a capacitor hold if it has 4.5 billion (4.5x109) elementary
charges (electrons)?
5. A 9.0 volt battery is connected in a series to four identical 4.00 ohm resistors connected
in parallel to each other. What are the current and power through the circuit?
6. A 0.25 C positive charge moves to the south at a speed of 250 m/s and enters a region of
uniform magnetic field. It experiences a force of 20 N down. What is the magnetic
field?
7. A straight current-carrying wire is in a uniform magnetic field oriented at right angles to
the wire. If 1.14m of wire is in the 0.72-T field, and the force on the wire is 0.33 N, what
is the current in the wire?
Name ____________________________________________________ period _________
3rd 9 weeks test CALCULATION practice
Part 2: in class practice
Instructions: Show all formulas and work on a separate sheet and staple to this handout.
Show answers with units in the space provided, No work on separate sheet = no credit.
Date: Wednesday 2/27/13 Finish for homework if needed
1. Two identical insulated metal spheres are separated by 10.0 cm. Equal charges are placed
on each sphere, which results in a force of 2.3 x 1014N. Each charge is tripled in size, and
the distance between the spheres is increased to 20.0 cm. What is the magnitude of the
force on the sphere after the changes have been made?
2. A particle of ink in an ink-jet printer carries a charge of -8 x10-13 C and is deflected onto
paper with a force of 3.2 x10-4 N. Find the strength of the electric field
3. A piece of fur is rubbed against a plastic rod. The resulting charge on the fur is +24
microCoulombs. What charge does the rod acquire?
4. How many electrons would need to be removed from an object to produce a charge of
8.00 microCoulombs? (1 microCoulomb = 1 x 10-6 Coulombs)
5. A 420 ohm resistor draws 0.52 A of current. What is the power dissipated by this resistor
in watts?
6. An electron travels at a uniform speed of 3.0 x 106 m/s to the east. If then enters a
uniform magnetic field and experiences a maximum force of 5.0 x 10-19 N. What is the
magnetic field?
8Ω
7Ω
9V
10Ω
5Ω
7. Use the diagram above to answer the following questions
a. Find the total resistance of the circuit shown above.
b. What is the amount of current flowing through the system?
c. What is the potential difference across the 10 ohm resistor?
8. A beam of protons travels at 3.5 × 106 m/s through a uniform magnetic field of 5.7×10-2
T. The beam of electrons is perpendicular to the field. How strong is the force acting on
each proton?
9. An electron moving at 5.6×107 m/s travels through a uniform magnetic field of 1.4 T at
right angles to the field. How strong is the force that acts on the electron?
10.A 10-m long wire carrying 5 A of current is at right angles to a uniform magnetic field of
0.01 T. What is the magnitude of the force on the wire?
11.A straight wire that carries a 4.6-A current is in a uniform magnetic field oriented at right
angles to the wire. The magnetic field has a strength of 1.2 T. If the force exerted on the
wire is 0.60 N, what length of wire is in the magnetic field?
Name _______________________________________________ period _________
3rd 9 weeks test STATIONS practice
Instructions:
 Thursday= rotate in groups to different stations, answering the questions as a group and
taking notes.
 Friday= answer questions below based on group station activities on Thursday
DUE: Monday 3/4/13
Open-ended Questions: write your answers in the space provided
1. What process is being described?
“A charged rod is brought close to, but does not touch, an uncharged sphere, while a third object
touches and is then removed from the sphere, leaving behind an unbalanced charge”
2. According to Coulomb's Law, which should the student do to increase the electrical force of
repulsion between these balloons?
3. What is the function of an electroscope? Explain how is works.
4. A capacitor is a device that can store electric charges. In a common design, charge is conducted to
non-touching parallel plates where it is stored for use later. In order to move a charge in and out of
the capacitor plates, what type of material must be between the two plates?
5. In the water flow analogy, the current in a circuit is analogous to _______________ and resistors
in a circuit are analogous to _________________________.
6. What is generally the most dangerous aspect of electricity: the voltage or current? Why?
7. One light bulb in the kitchen burns out and suddenly several lights go out in the house. This would
provide evidence that the bulbs were wired in what kind of circuit?
8. Explain the difference between a conductor and provide 2-3 examples of each.
Look at the formulas I=V/ R and P=VI
9. What happens to power when:
a. Current increases?
b. Voltage increases?
c. Resistance increases?
Using a 6V battery and 3 resistors:
10. Draw a series circuit and explain what it means for circuit elements to be in “series with each
other".
11. Draw a parallel circuit and explain what it means for circuit elements to be in “parallel with each
other".
12. Which type of circuit shares the current?
13. Which type of circuit would decrease the total current, I, flowing through this circuit?
True or False Questions: write the answer in the blank provided
14. ____________True or false: In order to avoid being shocked when working with live circuits, you
should only touch bare wires.
15. ____________Voltmeters are used to measure the potential difference across circuit components
such as resistors. Voltmeters have high resistance and are placed in parallel with the resistor.
16. ____________Most good insulators of electricity are also good conductors of heat.
17. ____________In order to make a stronger electromagnet, you must use more turns (wraps) of
wire, use an iron core instead of a wooden, and use more current through the wire.
Use the picture below for the true/ false statements in questions 18-21.
18. ____________The iron in the nail makes the magnet stronger.
19. ____________The head of the nail is always the S pole regardless of how the battery is hooked up
or the wires are wound.
20. ____________The point of the nail is the N pole of this electromagnet.
21. ____________Electromagnets are magnetic dipoles.
Multiple Choice
22. In which situation will a charged particle experience a force from interacting with magnetic fields?
a. a charged particle moving parallel to magnetic field lines
b. a charged particle moving perpendicular to magnetic field lines
c. all of the above
d. none of the above
23. A long, straight wire carries an electrical current. Which is the BEST description regarding the
magnetic field created by the current?
a. A straight wire does not create magnetic fields.
b. It is weak but parallel to the wire, in the direction of the current.
c. It circles the wire forming a loop.
d. It spirals around the wire like a slinky, with the current in the center.
24. Which pole of the magnet is the North pole, and in which direction does the magnetic field point
between the poles?
a. Left pole is N, magnetic field points to the right.
b. Left pole is N, magnetic field points to the left.
c. Right pole is N, magnetic field points to the right.
d. Right pole is N, magnetic field points to the left.