Download Honors physics Circuits and Magnetism Study Guide Textbook

Honors physics
Circuits and Magnetism Study Guide
Textbook Chapters 17, 18, 19, and 20
1. Electric potential is defined as the electric potential __energy___ associated with a
charged particle in an electric field divided by the ___charge_____ of the particle.
2. Since potential difference is measured in _____volts_______, it is often called
___voltage____.
3. Electric _____current______ is the rate at which electric charges pass through a given
area. It is measured in ___amperes____.
4. Resistance is defined as the ratio of ____voltage____ to ____current____ and is
measured in _____ohms__________.
5. Electric power is the rate at which charge carriers do _____work______ and is
measured in _____watts_____.
6. When two or more components of a circuit provide a single path for current, they are
said to be in _____series______.
7. When two or more components of a circuit provide separate conducting paths for
current, they are said to be in _____parallel______.
8. In a series circuit, _____current_____ is the same everywhere in the circuit, but the
____voltage_______ across each component can vary.
9. In a parallel circuit, ______current__________ can vary at different parts of the
circuit, but the _________voltage___________ across each component is the same.
10. Magnetic field lines appear to begin at the _____north______ pole of a magnet and end
at the ______south_________pole.
11. Since opposite poles ______attract______, a compass needle indicates the earth’s
magnetic south pole is located near the geographic ______North________ Pole.
12. Magnetic ________poles_____________ always exist in pairs.
13. A long, straight _____current________- carrying wire has a cylindrical _____magnetic
field_____.
14. If a long, straight wire is bent into several closely spaced loops, the resulting device is
called a _____solenoid_________.
15. The magnetic field of a solenoid can be increased by inserting an ____iron rod______
through the center of the coil.
16. A charge moving through a magnetic field experiences a ____force__________.
17. The unit of magnetic field strength is the _______tesla_______________.
18. To determine the direction of the magnetic force on a moving charge or a current, use
the ____right_____-hand rule: If your _____fingers_____ are pointing in the direction
of the magnetic field and your _______thumb________ is pointing in the direction of
the motion of the charge or the current, then the force is directed out the
____palm_______ of your hand.
19. The process of inducing a current in a circuit by changing the magnetic field that passes
through the circuit is called ______electromagnetic induction_______.
20. Pushing a bar magnet into a coil of wire connected to circuit will induce a current in the
wire. Doubling the speed of the magnet will ____double____ the current. Doubling the
number of loops in the coil will _____double____ the current.
21. A _____generator_________ is a machine that converts mechanical energy into
electrical energy by turning a wire loop in a ____magnetic field_____.
22. ______motors__________ are machines that convert electrical energy to mechanical
energy. They function like generators in reverse: a ___current_____is supplied to a loop
in a magnetic field, and the magnetic force on the loop causes it to
____rotate__________.
23. A ______transformer________ is a device that increases or decreases the emf
(voltage) of alternating current. In its simplest form, it consists of two coils of wire
wound around a core of soft iron.
24. To reduce energy lost as resistive heating in transmission lines, power companies use a
high _____voltage______ and a low ______current________ when transmitting power
over long distances. The use of _______alternating_________ current allows
transformers to step up or step down the emf (voltage).
Problem solving
25. What is the potential difference across a 4.0  resistor that carries a current of 1.5 A?
26. If a 100 W light bulb operates at a voltage of 120 V, what is the current in the bulb?
27. Three resistors having values of 3.0, 4.5 and 7.0  are connected in parallel. What is
their equivalent resistance?
28. A 12 V battery is connected to a 7.2 Ω resistor and a 1.8 Ω resistor arranged in series.
What is the voltage across the 1.8 Ω resistor?
29. A 7.0 T magnetic field acts in a direction due north. An electron is traveling due east at
3.6 x 106 m/s. What is the magnitude and direction of the force acting on the electron?
(The charge of an electron is -1.60 × 10-19 C)
30. A wire 0.80 m long carrying a current of 25 A is at right angles to a uniform magnetic
field. The force on the wire is 0.067 N. What is the strength of the magnetic field it is
in?