Circuits

Question 1

the movement of charge that occurs between two points that have different electrical potentials

Answer 1

current

Question 2

magnitude of current (I)

Answer 2

I = Q / ∆t

where:
Q = charge passing through conductor

Question 3

the reciprocal of resistance

Answer 3

conductance

Question 4

allow current to flow through them

Answer 4

conductive materials

Question 5

type of conduction:

relies on uniform movement of free electrons in metallic bonds

Answer 5

metallic conduction

Question 6

type of conduction:

relies on the ion concentration of a solution

Answer 6

electrolytic conduction

Question 7

materials that do not conduct a current

Answer 7

insulators

Question 8

charge flows in one direction only

Answer 8

direct current (DC)

Question 9

charge flow changes direction periodically

Answer 9

alternating current (AC)

Question 10

two rules that deal with the conservation of charge and energy within a circuit

Answer 10

Kirchoff’s laws

Question 11

states that the sum of currents directed into a point within a circuit equals the sum of currents directed away from that point

Answer 11

junction rule

Question 12

junction rule

Answer 12

I (into junction) = I (out of junction)

Question 13

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

Answer 13

loop rule

Question 14

loop rule

Answer 14

V (source) = V (drop)

Question 15

the opposition to the movement of electrons through a material

Answer 15

resistance

Question 16

conductive materials with a moderate amount of resistance that slows down electrons without stopping them

Answer 16

resistors

Question 17

depends on resistivity (ρ), length (L), and cross-sectional area (A) of the material of the resistor

Answer 17

resistance of a resistor (R)

Question 18

resistance of a resistor (R)

Answer 18

R = ρL / A

where:
ρ = resistivity
L = length
A = cross-sectional area

Question 19

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

Answer 19

Ohm’s law

Question 20

Ohm’s law

Answer 20

V = IR

where:
V = voltage drop
I = current
R = resistance

Question 21

power (P)

Answer 21

P = W / t = ∆E / t

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

Question 22

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

Answer 22

resistors in series

Question 23

total voltage/resistance of resistors in series

Answer 23

V(s) = V(1) + V(2) + V(3) + … + V(n)

R(s) = R(1) + R(2) + R(3) + … + R(n)

Question 24

cause a decrease in equivalent resistance of a circuit

Answer 24

resistors in parallel

Question 25

total voltage/resistance of resistors in parallel

Answer 25

V(p) = V(1) = V(2) = V(3) = … = V(n)

1/R(p) = 1/R(1) = 1/R(2) = 1/R(3) = … = 1/R(n)

Question 26

have the ability to store and discharge electrical potential energy

Answer 26

capacitors

Question 27

is determined in parallel plate capacitors by the area of the plates and the distance between the plates

Answer 27

capacitance

Question 28

capacitance (C)

Answer 28

C = Q / V

where:
Q = charge stores on one plate
V = potential difference (voltage) across capacitor

C = ε(o) A / d
where:
ε(o) = permittivity of free space (8.85 x 10^-12 F/m)
A = area of overlap between plates
d = distance between plates

Question 29

potential energy stored in a capacitor

Answer 29

U = 1/2 CV^2

where:
C = capacitance
V = potential difference (voltage)

Question 30

cause a decrease in the equivalent capacitance of a circuit

Answer 30

capacitors in series

Question 31

capacitors in series

Answer 31

1/C(s) = 1/C(1) + 1/C(2) + 1/C(3) + … + 1/C(n)

Question 32

sum together to create a larger equivalent capacitance

Answer 32

capacitors in parallel

Question 33

capacitors in parallel

Answer 33

C(p) = C(1) + C(2) + C(3) + … + C(n)

Question 34

insulators placed between the plates of a capacitor that increase capacitance by a factor equal to the material’s ____ constant (𝜅)

Answer 34

dielectric materials

Question 35

capacitance with dielectric material

Answer 35

C’ = 𝜅C

where:
C’ = new capacitance with dielectric
𝜅 = dielectric constant
C = original capacitance

Question 36

are inserted in series in a circuit to measure current; they have negligible resistance

Answer 36

ammeters

Question 37

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

Answer 37

voltmeters

Question 38

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

Answer 38

Ohmmeters