physics 1B concepts
A real battery can be visualized an ideal EMF in series with a(n) _______ __________. The terminal voltage of a battery is taken across its __________ __________ an includes the effect of its __________ __________.
"internal" resistance external terminals internal resistance
Two or more resistors in parallel havean equivalent resistance given by _____(formula)_____, and will be ___{larger / smaller}___ than any of the individual resistances.
(1/Req ) = (1/R1) + (1/R2) + (1/R3) +.... smaller
Capacitors in series can be replaced by a series equivalent capacitor whose value is given by :
1/Ceq = 1/C1 + 1/C2 +...
The SI unit for current is the __________ which is equal to 1 __________ per __________.
Ampere Coulomb second
The magnitude of the magnetic field due to a current can be found by two different methods : ___-____ law or ____ Law.
Biot-Savart Ampere's
Capacitors in parallel can be replaced by a parallel equivalent capacitor whose value is given by :
Ceq = C1 + C2 +...
an electric field some distance r, from a charge Q, is given as:
E=keQ/r^2
An ideal voltage source is described by an __________ that serves as an "enforcer of voltage". An ideal ______ will provide whatever current is necessary to maintain its rated voltage difference across it.
EMF, ℰ EMF
Capacitance is measured in units of _______, or more typically micro_______, nano_______, or pico_______.
Farads
Circuits involving multiple voltage sources can be solved using ____ Rules.
Kirchhoff's
_____ ______ Rule states that at any wire junction, the sum of the currents must equal ____. That is, the total current into the junction must ____ to the total current out of the junction.
Kirchhoff's Current (Junction) Rule (KJR) zero equal
____ _____ Rule states that around any closed loop, the sum of the voltage differences must ____ zero. To apply this rule, you must first (arbitrarily) choose a proposed direction for the current through each element and (arbitrarily) choose a direction (CW or CCW) for each loop.
Kirchhoff's Voltage (Loop) Rule (KLR) equal
The sum of the magnetic force and electric force on a moving charged particle is called the ___ force. The electric force is ___ of the charged particle's velocity, but the magnetic force is ___ on the charged particle's velocity.
Lorentz independent dependent
The power associated with a circuit element may be calculated by the relationship :
P = IΔV
Two or more resistors in series have an equivalent resistance given by : ____(formula)______ , and will be ___{larger / smaller}_______ than any of the individual resistances.
Req = R1 + R2 + R3 + .... larger
If a charged particle of mass, m, and charge, q0, is place in an electric field, E, it will experience an acceleration given by Newton's second law:
a=Fe/m= q0E/m
To apply Ampere's law, draw an imaginary ____ that encircles some cross-section(s) of the current carrying wire in a way that the magnetic field is known (by ____) to be ___ or ____ over different segments of the loop.
amperian loop symmetry constant zero
There are three ways to increase the capacitance of a parallel plate capacitor : (1) increase the plate __________, (2) decrease the plate _______, (3) insert a(n) _______ inside the gap with high _____________, ____>1.
area separation dielectric dielectric constant k
Capacitors in series must have the same ______ on each capacitor.
charge
the number of electric field lines is proportional to its ___
charge
An electric current in a conductor is equal to the amount of __________ that passes through a cross-sectional area of the conductor in a given __________.
charge period of time
The magnitude of the magnetic force on a moving charged particle is proportional to four quantities: (i) the ___ of the particle, (ii) the charge's ____, (iii) the ___ of the magnetic field, and (iv) the ___ of the angle between the ___ vector and the ____ vector.
charge velocity magnitude sine magnetic field velocity
Capacitance is a measure of ___ per ____. That is, the capacitance of a capacitor is the amount of ____ that can be stored when a particular ____ is applied across its two conductors (plates).
charge voltage charge voltage
The {charge on / voltage across} the parallel equivalent equals the sum of the charges { on/across} the capacitors that it replaces.
charge on on
A magnetic field can be produced by moving ___, such as the ____ in a wire.
charges current
Two like charges have the greatest potential energy when they are very (far apart/ close together).
close together
Gauss's Law states that the electric flux through any __________ surface is equal to the ________________ (divided by the constant, ε0).
closed net enclosed charge
Electrical __________ is the inverse of electrical resistivity (__= 1/ρ) .
conductivity σ
The current right-hand-rule states that if your point your outstretched thumb along the wire in the direction of the ___, your fingers will curl in the circulation direction of the _____.
conventional current magnetic field lines
Electrical resistance, R, is a measure of how much a circuit element reduces __________ through the circuit. Resistance on an element depends on both ______________ and _______________ effects.
current material (resistivity, ρ) geometric (length, area)
Coulomb's Law
describes the electric force between two charged particles; Fe = ke q1q2 / r^2
The _____________________ is a property of an insulator that describe how much it increases the capacitance of a capacitor when inserted between the plates.
dielectric constant
The _____________________is a property of an insulator that describes how strong of a(n) __________ that it can withstand before the material "breaks down" and becomes conducting. (a lightning strike occurs across it).
dielectric strength an electric field
When a previously-charged capacitor is connected in a closed loop to a resistor, then capacitor will ___ through the resistor. Initially, the current through the resistor is ___, but as time progresses, both the charge on the capacitor and the current through the resistor gradually ____.
discharge large fall to zero
Microscopically, the average velocity of an electron in the direction of the current is called the ______ ________, which is typically _{very slow / equal to / very fast }_ (compared to) the speed of an electrical signal in a circuit.
drift velocity very slow
The time-dependent behavior of RC circuits is characterized mathematically by exponential charging and discharging :
e^-t/τ, where τ = RC.
Equipotential lines indicate regions that are at the same value of ____ - they are analogous to contours of constant altitude on a geographic contour map.
electric potential (voltage)
Power has the units of ___ per ___. The SI unit of Power is ___. 1 ___ = 1 ___ / ___.
energy time Watts Watt Joule second
In steady state, any excess charge (positive or negative) on a conductor will reside ____________________.
entirely on its outer surface
Two unlike charges have the greatest potential energy when they are very (far apart/ close together).
far apart
the electric field is a map of the ___ that would be experienced by a ___ placed at any location
force +1C test charge
A current-carrying wire in a magnetic field will experience a ___ on the wire whose magnitude is proportional to four quantities: (i) the ___ (ii) the ___ of the wire exposed to the field, (iii) the ____, and (iv) the __ of the angle between the directions of the ___ and the ____.
force current, I length, l, of wire exposed magnitude of the magnetic field sine magnetic field, current
In steady state, excess charge density on the surface of an irregularly-shaped conductor will be __________ at edges, sharp points, or tightly curved corners. The electric field outside the conductor will be _________________ around these sharp regions of high charge density.
greatest more concentrated
Kirchhoff's Voltage (Loop) Rule, when the loop runs in the same direction as the current, then a battery or EMF provides a(n) _____ in voltage while a resistor provides a(n) ___ in voltage. When the loop runs in the opposite direction of the current, then the reverse is true.
increase decrease
Electrical resistivity generally __{increase/decreases}___ with temperature. The ____________________ is a material-dependent property that describes the rate of change in resistivity with increasing temperature.
increases temperature coefficient of resistivity, α
Because of its non-zero _______ _______, the terminal voltage of a real battery will be ___(</ >)___ or equal to the ideal EMF, depending on the "load" (the effective resistance of the circuit to which it is attached).
internal resistance <
A pair of charges has an electric P.E. that is{directly / inversely} proportional to their {separation / separation-squared}.
inversely separation
When an EMF is connected to a series RC circuit, the current through the resistor is initially ___ but the charge on the capacitor is initially ___. As time progresses, the charge on the capacitor ___, as does the ___ across the capacitor; and as a result, the current through the resistor goes ___. Eventually, the capacitor reaches a maximum charge of Q = ℰ C, the voltage across the capacitor becomes ___ to that of the EMF source, ℰ, and the current through the resistor ____.
large small (zero at very first instant) increases voltage down equal falls to zero
The Biot-Savart law gives us the infinitesimel ____ contribution at a point, P, some distance, r, from an infinitesimal segment (ds) of a wire carrying a current, I.
magnetic field
We can find the total ___ due to any wire by integrating the contributions given by Biot-Savart's law along the _____ of the wire.
magnetic field entire length
the density of electric field lines represents the local ___ of the electric field.
magnitude
Electric flux depends on the _____ of the electric field, and the ____ and ____ of the surface.
magnitude area orientation
In a uniform magnetic field, B, a charged particle or mass, m, moving with velocity, v, perpendicular to the magnetic field will undergo uniform circular motion with a radius, r, found by equating the magnitude of the ____ to the ____.
magnitude of the magnetic force centripetal force required
Electrical resistivity depends only on the _______________ and its ______________.
material used temperature
A loop of current in an external magnetic field can experience a torque that will cause it to rotate to align with the magnetic field in such a way that _____ the loop area through which magnetic field lines pass. (i.e., so that its magnetic moment vector aligns with the _____)
maximizes magnetic field
The electric potential nearby a negative point charge is a large ____ value and ____ towards zero as you move infinitely far away from the negative point charge.
negative increases
A charged particle moving parallel or anti-parallel to a magnetic field will experience ____ magnetic force. A charged particle moving perpendicular to a magnetic field will be ___ with ____ force.
no deflected the maximal
Electric flux is proportional to the __________ of electric field lines that cross a surface.
number
the tangent to the electric field lines represents the local ___ to the electric field
orientation
If two or more resistors are connected so that the front (top) end of each resistor is connected to each other only by wires (through wire junctions) and the back (bottom) end of each resistor is connected to each other only by wires (through wire junctions), then they are said to be connected in __________.
parallel
A vacuum-filled ______________ capacitor is the simplest example of a capacitor consisting of two plates of area A separated by a gap of width d. Its capacitnce is given by:
parallel plate C = ε0A / d.
In steady state, the electric field immediately outside a conductor is {parallel/perpendicular} to the local surface.
perpendicular
In the presence of a magnetic field, a moving charge will experience a magnetic force that is directed ___ to both the magnetic field and the instantaneous velocity vector of the particle. There are two possible directions for this ____ magnetic force (e.g., up/down, left/right, in/out, east/west, north/south). The appropriate choice between these two possible directions is given by the force right-hand-rule
perpendicular perpendicular
Electric flux is a measure of the _____________ component of the electric field passing through a __________.
perpendicular surface area
A region that contain both a magnetic field and an electric field oriented ___ to each other, can act as a ____ selector for particles injected ___ to both fields.
perpendicular velocity perpendicular
The electric potential nearby a positive point charge is a large ____ value and it ____ towards zero as you move infinitely far away from the positive point charge.
positive decreases
electric field points away from ___ charges and toward ___ charges.
positive negative
We can associate a "magnetic moment" vector, (mu vector) with a current loop which has a magnitude ____ to the current and the area of the loop, and whose ____ is given by the right-hand-rule. (curl your right fingers in the sense of the ____; your outstretched thumb aligns with the _____)
proportional direction current loop mu-vector
the strength of an electric force falls off ___ with distance
quadratically
A __________ is a circuit element that provides electrical resistance in a circuit.
resistor
An RC circuit combines a ___ and a ___ in a single circuit and introduces a characteristic ___ to the circuit. The characteristic ___ of an RC circuit is given by:
resistor capacitor time time τ = RC and has the units of seconds
For a loop of current, the magnetic field inside the loop due the current will all be directed in the ____ direction (upwards vs downward), but is non-uniform and divergent (angles away from the center)
same general
Electric potential (voltage) is a {scalar / vector} quantity. The voltage due to multiple charges is the {vector / algebraic} sum of the electric potential (voltage) due to each charge individually.
scalar algebraic
If two or more resistors are connected in a single line with only simple wires (with no junctions) between them, then they are said to be connected in __________.
series
An (infinitely) long, tightly wound spiral of current is called an (ideal) ___. The solenoid has a uniform magnetic field inside of it that is all directed _____ to the axis of the spiral.
solenoid parallel
The magnetic field lines that describe the magnetic field around a ____ form circles centered on the wire and that circulate around the wire in a direction given by the current right-hand-rule.
straight current-carrying wire
The area vector of a surface has a magnitude equal to the ____ and a direction that is ____ to the surface. The area vector points ____ for closed surfaces.
surface's area perpendicular outward
Ampere's law allows us to easily calculate the magnetic field due to current-carrying wires if the wire configuration has sufficient ____, such as a single long straight wire, a ____, or a ____.
symmetry solenoid toroid
The direction of the magnetic field at any point is ____ the direction of the magnetic field line at that point.
tangent
the electric force between two particles acts along ______?
the line that connects the centers of both charges
electric field is the electric force on a test charge divided by ___; given as ____
the magnitude of that test charge E=Fe/q0
Electric field is a ___ quantity with the units ___
vector Newtons/ Coulomb (N/C)
A mass spectrometer utilizes a ___ selector followed by the ___ motion of a particle in a magnetic field to separate charged molecules and atoms based on the charge-to-mass ratio.
velocity circular
Ohm's Law describes the a linear relationship between the __________, __________, and __________ in a circuit: ____(formula)______. An __________ material is one that obey's Ohm's Law.
voltage current resistance ΔV = IR ohmic material
The {charge on / voltage across} the series equivalent equals the sum of those { on/across} the capacitors that it replaces.
voltage across across
Capacitors in parallel must have the same ____________________________.
voltage difference across them
An electrical circuit can be driven by a _____________ that provides the "push" on electrical charges so that they flow as current through the circuit.
voltage source
In steady state, the electric field is __________ everywhere inside of a solid or hollow conductor
zero
When a test charge moves from a position at one electric potential (voltage) to another, its change in electric potential energy is given by :
ΔUe = q0 ΔV