Electricity

Question 1

Whats the resistance in a parallel circuit?

Answer 1

1/Req=1/R1+1/R2

Question 2

Whats the resistance in a series circuit?

Answer 2

Req=R1+R2

Question 3

What is delta v in parallel circuit?

Answer 3

The same in both branches. Vbat=V1=V2

Question 4

What is delta v in series?

Answer 4

Veq=V1+V2

Question 5

What is current in parallel?

Answer 5

Ieq=I1+I2

Question 6

What is current in series?

Answer 6

I1=I2

Question 7

Power of battery?

Answer 7

Pbat=I*Vbat (watts or J/s)

Question 8

Power dissipated by a resistor?

Answer 8

Pr=I*deltavR=I^2R=(deltavR)^2/R

Question 9

How do you solve for the specific resistance/amps/deltav per each component in a circuit?

Answer 9

Setup a table and use the equivalent equations to fill it out. “Unfold” the simplified circuit out

Question 10

What is capacitance equivalent to by definition?

Answer 10

C=Q/V (F)

Question 11

PE stored in capacitor is…

Answer 11

1/2QV

Question 12

What is the capacitance of a capacitor

Answer 12

C=kE0(A/D), if dielectrics arent involved, assume k is approx 1

Question 13

What is the unit F?

Answer 13

Farads

Question 14

What is capacitance in series?

Answer 14

1/Ceq=1/C1+1/C2

Question 15

What is capacitance in parallel?

Answer 15

Ceq=C1+C2

Question 16

What is voltage in series?

Answer 16

Veq=V1+V2

Question 17

What is voltage in parallel?

Answer 17

V1=V2

Question 18

What is charge in series?

Answer 18

Q1=Q2

Question 19

What is charge in parallel?

Answer 19

Qeq=Q1+Q2

Question 20

Whats the voltage/work done by the battery when the first electron enters a capacitor? The last?

Answer 20

First electron: W=q(0)=0
Last electron: W=qdeltav=qV

Question 21

What is current defined as?

Answer 21

I=deltaq/deltat

Question 22

Resistance of a wire equation

Answer 22

R=p*(L/A)

Question 23

What happens when a capacitor is charged up all the way?

Answer 23

It has the same voltage across it as the battery/branch voltage source. The top plate connected to the positive end is 12v

Question 24

Whats the chemistry behind the charge of a capacitor balancing out?

Answer 24

As electrons flow from the anode they build up charge on one plate of the capacitor building up anionic conduction material. That negative point charge induces an electric field which polarizes cations on the other end. Those free electrons then complete the redox reaction. Since the electric field is preserved when disconnected from the battery as the electrons can’t form back stable matter, the charge will stay the same when disconnected but since the driving force only happens from the free energy of the chemical reaction, the voltage/potential stays the same when connected

Question 25

What correlates to brightness?

Answer 25

Power

Question 26

What are the equations for RC circuits

Answer 26

For discharging: Q=Q_max*e^-t/RC For charging: Q=Q_max*(1-e^-t/RC)

Question 27

What is the time constant of an RC circuit

Answer 27

If you form a closed kirchoff loop, it's the equivalent resistance of the circuit as if the capacitor was a battery. That's R, then C is the capacitance of the capacitor. T, the time constant is just RC

Question 28

What happens to the energy of a capacitor if you change the spacing?

Answer 28

It will affect the stored PE

Question 29

If you have an arbitrarily shaped conductor with a net negative charge, what is the electric potential inside the conductor?

Answer 29

Constant and negative

Question 30

What happens to the strength of the electric field between a capacitor? if the capacitance changes?

Answer 30

Nothing changes if connected to battery/constant voltage but it does change if there's a constant charge when it's disconnected