Circuits

Question 1

Current

Answer 1

the movement of charge that occurs between two points that have different electrical potentials. By convention defined by a positive charge from the high potential end of a voltage source to the low. In reality it is negatively charged particles (electrons) that move in a circuit, form low potential to high potential.

I = Q/Δt

Question 2

Current only flows..

Answer 2

in conductive material

Question 3

Metallic conduction

Answer 3

relies on uniform movement of free electrons in metallic bonds

Question 4

electrolytic conduction

Answer 4

relies on the ion concentration of a solution

Question 5

Insulators

Answer 5

are materials that do not conduct a current

Question 6

Kirchoffs laws

Answer 6

express conservation of charge and energy

Question 7

kirchhoffs junction rule

Answer 7

states that the sum of currents directed into a point within a circuit equals the sum of currents directed away form that point.
I into junction = I leaving junction

Question 8

Kirchhoffs loop rule

Answer 8

states that in a closed loop, the sum of voltage sources is always equal to the sum of voltage drops.
Vsource = Vdrop

Question 9

Resistance

Answer 9

is opposition to the movement of electrons through a material
R = pL/A

Question 10

resistors

Answer 10

are conductive materials with a moderate among to resistance that slow down electrons without stopping them. calculated using resistivity, length, and cross-sectional are of the material in question.

Question 11

Ohm’s law

Answer 11

states that for a given resistance, the magnitude of the current through a resistor is proportional to the voltage drop across the resistor .
V = IR

Question 12

Resistors in series

Answer 12

are additive and sum together to create the total resistance of a circuit

Question 13

resistors in parallel

Answer 13

cause a decrease in equivalent resistance of a circuit

Question 14

Across each resistor in a circuit…

Answer 14

a great amount of power is dissipated, which is dependent on the current through the resistor and through voltage drop across the resistor.

Question 15

capacitors

Answer 15

have the ability to store and discharge electrical potential energy

Question 16

capacitance

Answer 16

in parallel plat capacitors is determined by the area of the plates and the distance between plates
C = Q/V

Question 17

capacitors in series cause

Answer 17

a decrease in the equivalent capacitance of a circuit

Question 18

Capacitors in parallel

Answer 18

sum together to create a larger equivalent capacitance

Question 19

Dielectric materials

Answer 19

are insulators placed between the plates of a capacitor that increase capacitance by a factor equal to the material’s dielectric constant, k.
C’ =kC

Question 20

Ammeters

Answer 20

are inserted in series in a circuit to measure currents, they have negligible resistance

Question 21

Voltemeters

Answer 21

are inserted in parallel in a circuit to measure a voltage drop; they have very large resistance.

Question 22

Ohmmeters

Answer 22

inserted around a resistive element to measure resistance; they are self powered and have negligible π

Question 23

Voltage and cell emf

Answer 23

V=E cell -ir int

Question 24

Power

Answer 24

P = W/t = ΔE/t

Question 25

electric power

Answer 25

P=IV=I^2R=V^2/R

Question 26

Voltage drop across circuit elements (series)

Answer 26

Vs=V1+V2+V3+Vn

Question 27

Equivalent resistance in series

Answer 27

Rs=R1+R2+R3

Question 28

Voltage drop across circuit elements parallel

Answer 28

Vp=V1=V2=V3`

Question 29

Equivalent resistance parallel

Answer 29

1/Rp=1/R1 + 1/R2 + 1/Rn

Question 30

Capacitance based on parallel plate geometry eq

Answer 30

C=e0(A/d)

Question 31

electric field in a capacitor

Answer 31

E = V/d

Question 32

Potential energy of a capacitor

Answer 32

U = 1/2 CV^2

Question 33

Equivalent capacitance in series

Answer 33

1/Cs = 1/C1 + 1/Cn

Question 34

Equivalent capacitance in parallel

Answer 34

Cp = C1 + C2 + Cn