Download Magnetic Field

Name:
Period:
Electricity and Magnetism
Review
1.
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10.
Electrons and protons have electrical forces between them because they have _____________.
What is the charge on an electron? ________________________.
What is the charge on a proton? _______________________.
The flow of charges around a circuit is called _________________ and is measured in Amps.
In a series circuit with 3 resistors there are _______________ paths for current.
In a parallel circuit with 3 resistors there are _______________paths for current.
In order for a wire to be making a magnetic field there must be a __________________.
If you cut a permanent bar magnet in half you’ll be left with _______________________.
Magnetic induction means making current by moving a ____________near a conductor.
Transformers require AC power because the secondary coil only responds to _______________
in the magnetic field.
11. Fill in the following table.
Thing
Symbol
Magnetic Field
B
V
Resistance
Volts
R
E
Current
Unit
N/C
Amps
Charge
12. Anthony the tightrope walker has a mass of 85 kg. He is hovering on a wire with 2.0 Amps of
current. What is the magnitude and direction of the magnetic field?
13. A 12 cm long stream of electrons is headed toward a computer screen. They form a current of
–1.0x10-3 A. If someone brings a magnet with a field of 3.0 Tesla near the stream what is the
most force (magnitude and direction) that the electrons will feel?
14. Two 35 C charges are 2.3x104 m apart. What is the force between them? Is it repulsive or
attractive?
15. Draw the electric field:
a) Around 2 like charges
b) Around 2 opposing charges
16. Draw a magnetic dipole field around a bar magnet.
17. The following circuit is constructed using a 12V battery and three 6.0 resistors. What are Req
and the current that flows out of the battery?
18. What is the voltage across the first resistor in the cicuit above?
19. A transformer has 2500 turns on the primary side and 25 turns on the secondary side. A 120V
of potential is put across the primary:
a) what voltage appears on the secondary side?
b) What is the current is the primary and secondary sides?
c) What is the power for the primary and secondary sides?
20. A 1.0 m wire is coming out of the page at you. A 3.0 T magnetic field is going from left to right
at 4.0 m/s. What is the current induced in the wire?
21. A TV is shooting electrons through it a CRT. What is the magnitude and direction of the
magentic field, if the electrons are accelerated to a speed of 1.5 x 105 m/s and feel a force of
25.0 N pushing them towards the top of the screen.
22. A portable lamp has three bulbs wired in series: one bulb has a resistance of 96 Ω, one bulb has a
resistance of 48 Ω, and one bulb has a resistance of 29 Ω. If the voltage across the lamp is 115 V, what is
the current through the lamp’s circuit?
23. A 10 Ω
Ω
Ω
connected in parallel
across a potential difference of 12 V. What is the equivalent resistance?
24. Two bulbs are wired in parallel: one bulb has a resistance of 3.3 Ω, and the other bulb has a resistance of
4.3 Ω. If the voltage across the circuit is 1.5 V, what is the current through each
bulb?
1. .
a. Draw a series circuit with 2 resistors and a 10.0 V battery.
b. Find Req as well as the currents and voltages for all circuit elements.
c. What is the power dissipated by the battery?
R
V
I
2. .
Battery
Req=
10.0 V
R1
6.00Ω
R2
3.00Ω
a. Draw a parallel circuit with 2 resistors and a 10.0 V battery.
b. Find Req as well as the currents and voltages for all circuit elements.
c. What is the power dissipated by the battery?
R
V
I
3.
R
V
I
25.
Battery
Req=
10.0 V
R1
6.00Ω
R2
3.00Ω
Find Req as well as the currents and voltages for all circuit elements.
Battery
Req=
12.0 V
R1
3.00Ω
R2
10.00Ω
R3
10.00Ω
R4
10.00Ω
R5
4.00Ω
A transformer has 550 turns in the primary coil and 2200 turns in the secondary coil. The primary is
connected to a 120 V plug and the secondary is connected to a 6.0 KΩ resistor. What are the currents through
the primary and secondary parts of the circuit?
26.
27. Make sure to look at pictures of magnetic forces in chapter 19