1what is current
the rate at which electric chargests move through a given area
2is current scalar or vector
scaalr
3what is current measured in
amperes
6How to measure dift speed
I = nAvq
7What does I=nAvq
I = current, n = number of charges, A = cross sectional area, v = drift speed of charges, q = charge
8what is drift speed
the speed at which electric hcarges move through an area in a wire
9what is direct current
a current in which all of the charges move in one direction
10resistance is measure in
ohms
11what is resistance
the ratio of the potential difference across a conductor to the courrent through it
12another name for voltage
potential difference
13what is Ohm's Law
the current in a conductor at constant temperature is proprtional to the potential difference across it
14when is something considered ohmic?
when the relationship between voltage and current is constant
15what is current
the rate at which electric chargests move through a given area
16what is resistivity
a property of a given material and is constant for a given measure
17resistivity measured in
ohm meters (O m)
18what is current
the rate at which electric chargests move through a given area
19What is power = to in terms of current and potential difference
P = IV
20What is power = to in terms of current and resistance
P = I^2 R
21What is power = to in terms of voltage and resistance
P = V/ R
22What is electric power measured in
Watts (W)
23what is series circuit
all current flows from one device to the next
24parralel circuit que
the current splits up and flows throgh different devices at the same time.
25in parallel, what happens with voltage when current splits
voltage stays the same in both current
26How to calc resistance in series
R(t)=R+R+R...
27How to calc resistance in parallel
1/R(t)=1/R+1/R+1/R...
28does ammeter has high or low resistance
low
30how is ammeter placed in the circuit?
series (within the circuit)
31how is voltmeter placed in the circuit
paralel
32What is Kirchoff's First law
the sum of the currents into a junction that equals the sum of the currents away from a junction. OR the total charge flowing into a junction = the total charge flowing away from the junction. This is equivalent to a statement of conservation of charge
33What is Kirchioff's second law also known as
voltage/look law
34time constant
the time for the voltage/charge/current in circuit to drop to 1/e or 37% of its intial value as the capacitro discharges. or time for vltagege/charge/current in circuit to increase to (1-1/e) or 63% of its final value as the cpacitor charges.
35in terms of potential energy, in a battery, neg to pos has
potential increasing
36if current and loop in same direction in a resistor
potential decreases
37if current and loop in opp direction in a resistor
potential increases
38To fine a matrix by 1x3, what eq u use
[A]^-1[B]
39to discharge energy of battery current flows
neg to post
40to recharge energy of battery current flows
neg to post
41what cant a variable resistor reach
O ohm or Max amt of Ohms
42whaat is a capacitor
an electrical device that stores charge on two conductors separated by an insulator (caled a dielectric). the amt of charge that can be stored on a given capactiro is related to the volaage across the two conductors and can be calc using this expression
43what is cpacitance
the charge per unit potential difference that can accumulate on a conductor.
44what is capacticance measured in
Farads (F)
45What is weird "E" mean
Dielectric Constnat
46What is dielectric
a substance that is a poir conductor of electricity but an defficient supporter of an electrostatic field. it is the material that fills the gap between the paltes of a cpaacitor
47how to calc parallel capatcience
C(t)= C+C+C...
48how to calc series capaticience
c(t) = 1/c+1/c...
49what does q = in terms of capaticence
delta q = q0(time)/(R)(C)
50Time constant (on a graph) will equal to RC at
37%
51time constant
the time for the voltage/charge/current in circuit to drop to 1/e or 37% of its intial value as the capacitro discharges. or time for vltagege/charge/current in circuit to increase to (1-1/e) or 63% of its final value as the cpacitor charges.