Conceptual Physics-Electricity Unit-Final Test Flashcards
To be studied in addition to Quiz 1 and 2 flash cards.
Current
Sym. I; U. Amps; USym. A
Voltage
Sym. V; U Volts; USym. V
Resistance
Sym. R; U. Ohms; USym. Ω
Power
Sym. P; U. Watts; USym. W
Energy
Sym. E; U. kilowatt hours or joules (watts per second); USym. kWh
What is the general trend and y intercept of a graph with current on the x-axis and voltage on the y-axis?
positive, (`0,0)
What is the relationship between resistance and current?
As resistance increases, current decreases (an inverse relationship).
What is the relationship between voltage and current?
As voltage increases, so does current (a direct relationship).
Why do we use fuses and circuit breakers?
to prevent electric fires
How are fuses and circuit breakers wired into a circuit?
in series
In a parallel circuit, where would you put a switch to turn off individual devices? A. on the wires connected to the generator/battery B. on the wires connected to the devices C. On the wires connecting the A and B wires
B
In a parallel circuit, where would you put a switch to turn off all the devices past a point? A. on the wires connected to the generator/battery B. on the wires connected to the devices C. On the wires connecting the A and B wires
C
In a parallel circuit, where would you put a switch to turn off all the devices? A. on the wires connected to the generator/battery B. on the wires connected to the devices C. On the wires connecting the A and B wires
A
What do we pay for when we use electricity on our electric bill?
electrical energy
How do you measure electrical energy?
In kWh, kilowatt hours (or joules)
Where does a hand generator get the energy needed to produce electric energy?
Mechanical energy in gears, which comes from kinetic energy of your hand turning, which comes from chemical energy in the food you ate, which comes from solar energy (from the sun)
What is the difference between a series circuit and a parallel circuit in terms of use, and how current and resistance are calculated?
Series circuits are used to wire in fuses and circuit breakers. Parallel circuits are used in homes and buildings.
In series, current is the same everywhere as the battery. In parallel, current is divided equally among the branches.
In series, resistance adds (goes up as you add resistance and current goes down). In parallel you add the reciprocals (1/R1+1/R2+1/R3…)? Then invert the answer? (goes down as you add resistance and current goes up).
How does a fuse work?
When the current goes too fast, it melts, “breaking” the circuit.
How does a circuit breaker work?
When the current goes too fast, it bends away from the other side, “breaking” the circuit.
How is an ammeter wired into a circuit?
In circuit
How is a voltmeter wired into a circuit?
in parallel
If a conductor is carrying 9 A of current, and then splits into two different wires, one of which carries 4 A, what current does the other wire have?
5 A
Does a line with a steeper incline have a greater or lesser resistance in a graph (x=current, y=voltage)?
A greater
What is Ohm’s Law?
It is the equation for voltage: Voltage=current x resistance (V=IR).
What is the equation for Power?
Power=current x voltage (P=IV)
What is the equation for Energy?
Energy=power x time (E=Pt)
If you are given voltage and power, what equation do you use to find what?
P=IV (power)
to find current
If you are given time and power, what equation do you use to find what?
E=Pt (energy)
to find energy
If you are given resistance and one other thing, what equation are you going to use?
V=IR (Ohm’s Law)
IF you are given current and voltage, which equations could you be using, depending on what you are looking for?
To find Power: P=IV (power)
To find Resistance: V=IR (Ohm’s Law)
What voltage does a typical household outlet have?
120 Volts
When given a list of appliances with their wattages, how could you find the overall wattage?
Add the watts
Energy cannot be blank or blank.
It can only blank blank.
Energy cannot be created or destroyed.
It can only change forms.
A circuit is a complete blank for blank current that contains a blank device and a method to convert electrical energy to blank blank blank blank.
A circuit is a complete path for electrical current that contains a generating device and a method to convert electrical energy to another form of energy.
Power is…
a measure of the rate at which energy is converted.
A generator converts energy from blank to blank
non-electrical to electrical
As current flow increases, power use blank
increases
Ohm’s law explains the relationship between blank, blank, and blank
current, voltage, and resistance
Power can be calculated as the product of blank and blank.
current and voltage.
As current flows through a circuit, the amount of voltage is blank until it reaches blank at the end of its path
reduced
zero
The current flowing through a circuit may separate along different paths, but the total amount of current…
will not change.
