1/32
Flashcards for Electricity and Magnetism Review
Name | Mastery | Learn | Test | Matching | Spaced |
---|
No study sessions yet.
What are sources of resistance in a circuit?
Wire length, wire area, wire density
What type of wire would have high resistance? Consider length and width.
Long, thin wire
What is the role of the battery?
Energy source
What is the difference between a conductor and an insulator? Give examples.
Conductor allows flow of electrons, insulator does not.
What is the difference between DC and AC current?
Direct and alternating
What are two ways to accidentally de-magnetize an object?
Drop it, heat it
Draw the magnetic field around a bar magnet.
Field lines extend from N pole and wrap into S pole.
What poles attract? Repel?
Like poles repel, opposites attract
How does distance & magnetic strength affect the strength of a magnetic force?
Force weakens with distance
What is an electromagnet?
Wire with current running through it, wrapped around an iron core
What can you do to increase the strength of an electromagnet (there are multiple ways)?
More voltage, more coils, shorter wire
Why does moving a magnet through a coil of wire generate a current? Think about what the electrons are doing.
The moving magnet pushes the electrons through the wire
What are 5 real life applications of electromagnets?
Medical field, junk yard
Compare the # of protons and electrons in a positive object
P > e
Compare the # of protons and electrons in a negative object
P < e
Compare the # of protons and electrons in a neutral object
P = e
What types of charges attract? Repel?
Opposites attract, like charges repel
What happens to the electric force if Q1 doubles?
F doubles
What happens to the electric force if Q1 and Q2 double?
F x 4
What happens to the electric force if Q2 is halved?
F is halved
What happens to the electric force if Distance doubles?
F = 1/4
What happens to the electric force if Distance triples?
F = 1/9
What happens to the electric force if Distance halves?
F x 4
What are the two general set ups for circuits? Be able to identify.
Series & parallel
What is the advantage of a parallel circuit?
Turn off one light the others
Describe the 3 ways an object can obtain a charge.
Friction, contact, induction
What is the only charging method that does not require objects to touch?
Induction
Charge can be lost through static discharge. Explain what this is and draw an example.
You are negatively charged + you touch a metal object, charges rush out of you and onto the metal object
What types of materials/elements make good magnets?
Iron, Nickel, Cobalt
What are magnetic domains?
Areas where the electrons are aligned
Write out Ohm's Law and the appropriate units for each variable.
V = IR ; Voltage (volts), Current (Amps), Resistance (Ohms)