D.c. Circuits

Front 1

Current

Back 1

I= q/ t

• Amperes= C/ time
• I= Change of q/ change of Time
  

Front 2

Ohm' Law

Back 2

V= IR

Voltage= Current x Resistance

Front 3

Resistance

Back 3

R= r (L/A)

r= resistance
L= Length
A= Area

Think about the water:
Increase Area than Resistance Decreases

Front 4

Resistors in Series

Back 4

Req= R1+R2+R3+R4+R5.....

• Add up Resistors in Series, thus more resistor in series means MORE Resistors and LESS Current.
• RAS

Front 5

Resistors in Parallel

Back 5

When you add more Resistors in Parallel you Decrease Resistance and Increase Current.

RIP- not cool.

Front 6

Electric Power

Back 6

Power= Watts= Energy/ time (J/sec)

P=IV=(I^2)R

P= (V^2)/ R

Front 7

Capacitance

Back 7

The ability to store charge over time.
C= Q/ V CONE-shape

C=AkE /d (CAKE)
- k= dielectric (Increases Capacitance)

Front 8

Potential Energy

Back 8

Storage Charge can be release at:
U= 1/2C(v^2)

Front 9

Capacitors in Series

Back 9

Front 10

Capacitors in Parallel

Back 10

Front 11

Dielectrics

Back 11

Cnew= kCold

Front 12

Kirchoff's 2nd Rule:
Sum of Voltage

Back 12

• The Sum of Voltage:
  The sum if Voltage Potential drop around a closed circuit loop.
  
• The sum of Voltage drops around a loop equals the sum of the voltage rises.
• Energy is conserved in one complete loop of a circuit. Energy lost in the resistors is gained back in the battery.
• The voltage drop is 8V and V rise is V=IR. Do we know I or R?

Front 13

Resistors SERIES

Back 13

• Vtotal= V1+V2+ V3+ V4+. They must total
• Rtotal= R1+2+R3+R4. They must total.
• There is only one path for current to flow thus all resistors see the same current.

IR1= V1
IR2= V2

Front 14

Resistors PARALLEL

Back 14

• 1/Rtotal= 1/R1+1/R2+1/R3
  
• Voltage: Vtotal=V1=V2=V3. Same across.
• Each has its own R but same V drop.

Front 15

Capacitor PARALLEL

Back 15

Ctota=C1+C2+C3+C4..
Voltage= V1=V2=V3

Front 16

Capacitor SERIES

Back 16

1/Cs= 1/C1+1/C2+1/C3
Vs= V1+V2+V3+V4

• When V drops across a series capacitor it must add up to Vtotal drop from the circuit.

Front 17

Dielectrics

Back 17

Lowering the voltage across, the charged-up capacitor has made "more" room for more charge!

Cnew=k(dielectric constant)Cold

Front 18

AC (Alternating Current)

Back 18

Current- (Same for Voltage).

Irms= Imax/ sqr(2)

or (Irms)sqr(2)= Imax

i= (Imax)(wt)

wt=2pi(ft)= angular frequency.

Front 19

The Capacitance

Back 19

The Capacitance of a capacitor is defined as the ratio of charge stored to the potential difference across the capacitor.

Front 20

Resistance (R)

Back 20

Can be thought of as the opposition to the flow of an electric current that occurs within a conductor.

R= p(L/ A) p= (Ohm)(m)

Increase Temp = Increase R

Front 21

Kirchhoff 1st Law: Current

Back 21

States that any junction in a circuit is the sum of current directed into that point equals the sum of currents directed away from that point.

Ia= Ib+ Ic