
Define circuit diagram
Draw the circuit diagram representations of the following:
 Circuit diagram: a logical picture of what is connected to what. The actual circuit may look different from the circuit diagram, but have the same logic and connections.

Draw the circuit diagram for the simple circuit shown and label the emf, R, and C of the capacitor. Also state the direction of the current
The wires, which in practice may bend and curve, are shown as ______ _______ connections between the circuit elements

 Current goes in a clockwise direction starting from the battery's positive terminal and ending on its negative terminal
 straightline connections

B. Its not connected to the negative end so its not a closed/complete circuit

Explain the Junction Rule
It is a statement of conservation of ______ and ______

Explain the Loop Rule
ΔV_{i} is the potential difference of the ___ ______ of the loop.
It is a statement of conservation of _____

The potential energy ______ whenever the charge moves through the potential drop.
ΔV _{R} for a resistor is always ________ (why?)
Why do we often speak of the "voltage drop" across the resistor?
ΔV _{bat} can be negative for a battery (why?)
In each diagram, ΔV = ______ and the circuit element is ______ from a to b, left to right
 decreases
 ΔV_{R} for a resistor is always negative because the potential in a resistor decreases along the direction of the current
 Because the potential across a resistor always decreases
 ΔV_{bat} can be negative for a battery because the current can go through a battery in a "wrong," positivetonegative direction when it is forced to do so by other, higher voltage batteries.
 ΔV = V_{b}  V_{a}
 traversed

The potential energy _______ whenever the charge passes through a battery from the negative terminal to the positive terminal
ΔV_{R} for a resistor increases (How is this possible?)
**pg 776
 increases
 ΔV_{R} for a resistor is positive because the potential in a resistor increases along the direction opposite the current

Since the potential drop in an ideal wire is ______, state the formula for:
ΔV_{loop} (4)
ε (1)
 zero

B. junction rule: 2.5  1.5 = 1.0 A

 A. The signs for both batteries are the same and both batteries are in series, so we can combine them into one battery of ε = 7.5 V
 Because all the resistors are in series ☞Kirchhoff's Law: Loop Rule
 ΔV_{loop} = ΔV_{bat} + ΔV_{R1} + ΔV_{R2} + ΔV_{R3} = 0
 ΔV_{loop} = ε + ΔV_{R1} ΔV_{R2} + ΔV_{R3} = 0
 (7.5 V) + (3.0 V) + (ΔV_{R2}) +(2.5 V) = 0
 2.0 V = ΔV_{R2}
**Note: If the symbols for the batteries were opposite it would be 4.5 V  3.5 V = 1.5 V and the 4.5 V battery would still be the dominant battery, so it would still dictate the direction of the current

 E. The dominant battery (9 V) dictates the direction of the current which will be clockwise. However, that current passes through the 6 V battery from + to  instead of  to +, so the current it will be a voltage drop: 9 V  6 V = 3 V
 OHM's Law:
 I = ΔV/R
 I = (3.0 V)/(3 Ω) = 1 A

 Low to high so
 ε  IR_{1}  IR_{2} = 0
 ε = +12V and IR_{1} = I(12) and IR_{2} = I(6)
 12  18I = 0
 I = 18/12 = 2/3
 So D.

A circuit with multiple elements can have different ways of connecting them.
Two basic ways of connection (name and draw them)

When two or more elements are connected endtoend, they are said to be in a ______ _______. There is NO _______ in between. Each element receives the same amount of _______ passing through it, but with different _______ across.
 series combination
 junction
 current
 potential

Same current pass through each resistors
Applying Kirchhoff's loop law:
___  ___  ___ = 0
ε = ___ + ___
We can replace two resistors with a single resistor having the value R_{eq} = R_{1} + R_{2}

The potential difference across the battery is also applied to the ________ ________ (___):
ε = _____
The equivalent resistance has the same effect on the circuit as the ______ _______ (why?)
 equivalent resistance (R_{eq}):
 ε = IR_{eq}
 series combination
 because it results in the same current (I) in the battery

The equivalent resistance of three or more resistors connected in series is:
R_{eq} = ?
The equivalent resistance of a series combination of resistors is the numerical sum of the _______ _________
It is always ________ than any individual resistance
 R_{eq} = R_{1} + R_{2} +R_{3} +...
 individual resistances
 greater

In a circuit with one bulb, a battery drives the current I_{A} = ____ through the bulb A.
In a circuit with two bulbs in series with the same resistance R, the equivalent resistance is R_{eq} = ___
The current running through the bulbs is:
I_{B} = ____ = ____
Since the emf is the same for both circuits,
I_{B} = ____
Thus, bulb B & bulb C are _____ bright, but they are ______ than bulb A because there is _____ current
 I_{A} = ε/R
 R_{eq} = 2R
 I_{B} = I_{C} = ε/2R
 I_{B} = 1/2(IA)
 equally bright
 dimmer
 less
 **Note: Bulbs of the same complete circuit are of the same current and hence brightness. All things equal, A should be brighter than B and C
 The Christmas bulbs are not in series, maybe every 3 or 4 bulbs are but not all of them

A battery is a source of ______ ______, not a source of _______.
The battery does provide the current in a circuit, but the amount of current depends on the _______.
The amount of current depends jointly on the ________ ______ and the ________ of the circuit attached to the battery
 potential difference
 current
 resistance
 battery's emf and resistance

Consider two resistor in a parallel combination:
Both resistors are connected directly across the terminals of the battery
The potential difference across the resistors are ____ _____:
ΔV = ____ = ____
ΔV is the ______ ______ of the battery
 the same
 ΔV = ΔV_{1} = ΔV_{2}
 terminal voltage

When charges reach a junction, the current splits into two parts, with some going toward R_{1} and the rest going toward R_{2}
Define Junction
 Junction: any such point in a circuit where a current can split

This split results in _____ current in each individual resistor than the current leaving the battery. The current (I) that enters point a must equal the total leaving that point:
I = ______ = ______ = _______
I_{1} is the current in R_{1} and I_{2} is the current in R_{2}
 less

The current in the equivalent resistance R_{eq} is:
I = ___ = ___
The equivalent resistance has the _____ _____ on the circuit as the two resistors in parallel
The equivalent resistance draws the same ______ from the battery
 I = ΔV/R_{eq} = ε/R_{eq}
 same effect
 current (I)

The equivalent resistance of 3 or more resistors in parallel is given by:
1/R_{eq} = ?
The inverse of the equivalent resistance of two or more resistors in a parallel combination is equal to the sum of the _______ of the individual resistances.
The equivalent resistance is always ______ than the smallest resistance in the group
Parallel resistors provide more _______ for charge to get through
An analogy is driving in heavy traffic (explain).

 inverses
 less
 pathways
 If there is an alternate route for cars (current) to travel, more cars (current) will be able to flow freely

