Circuits Flashcards
Current is the flow of ____ charge
Positive
How is current calculated?
I= Q/Δt
Current= Charge/time (usually Amps/secs)
Direct current flows in ____ direction while alternating current periodically _____
Same (the kind seen on the MCAT)
Changes direction
Most conductors have ____ resistance at high temperatures
High
Materials that don’t easily allow conduction (resist it) have ____ bound electrons
Tightly bound
This is why they resist flow, it’s hard to make the electrons line up properly to conduct electricity
Ohm’s law equation:
V=IR
Voltage= Current*Resistance
How is power calculated?
P=ΔE/t
(Change in energy/time) (Watts/secs)
Can also be calculated like : P=V^2/R (voltage squared/resistor)
In this type of resistor:
-Charge flows through each resistor —-Resistance is the sum of all the resistors
-The resultant equivalent resistance is the sum of all resistances
Series resistors
In this type of resistor:
-Charge follows a low or high potential path
-Voltage drop is the same no matter the path taken, since the starting and ending points are the same
-The resistance is calculated as the reciprocal of each of the resistors involved
Parallel resistors
This material acts as insulation for capacitors when they’re charging
Dielectric material
_____ can hold a charge at a particular voltage, like a defibrillator
Capacitors
In parallel plate capacitors, one plate gets a ____ charge while the other gets a ____ charge
Positive
Negative
What is the equation for capacitance?
C=Q/V
Capacitance= Charge/Voltage
Unit is Farad
What is the equation for capacitance involving the dielectric constant?
C’=kC
(New capacitance=dielectric constant*old capacitance)
This type of capacitor can’t store much charge because the voltage passes through all of them and has to share the voltage drop. It’s overall capacitance is calculated as a reciprocal ratio
Series capacitors
