Chapter 6 - Cirtcuits Flashcards
Current equation on SI unit
I = Q/∆t
the ampere: 1A = 1 C/s
Potential difference
Voltage
1V = 1J/C
EMF
Not actually a force, it is the potential difference when no charge is moving between the two terminals of a cell that are at different potential values
Think in terms of:
Pressure to move
Kirchhoff’s junction rule
Current into junction = current out
Kirchhoff loop rule
All the voltage gets used up around a closed circuit
*conservation of energy
Three properties of resistors summarized in the resistor equation
R = pL/A
p= résistivité L = length of resistor A = cross-sectional area
How does temp affect resistance ?
Most conductors have greater resistance at higher temp
Ohm law
V= IR
Power
rate at which energy is transferred or transformed
P = W/t = ∆E/t
How can you calculate the power of a resistor
P = IV
= I^2R = V^2/R
Does current change when it encounters a resistor or capacitor?
No
**potential energy changes (voltage)
How are capacitors in series calculated ?
1/Ct = 1/C1 + 1/C2+…
Like resistors in PARALLEL
How to calculate capacitors in parallel
Ct = C1+ C2 +…etc
Like resistors in series
Capacitance equation
C = Q/V
Capacitance (a Farad = 1C/V)
Q = charge (coulombs)
Équation for parallel plate capacitance
C = E0 (A/D)
E0 (Epsilon) = a constant given to us
A = area of overlap on plates
D = distance between plates
