Flashcards in Electric Circuits Deck (47):

1

## What is the equation for electric current?

###
I=Δq/Δt

Units: C/s or A (Amps)

2

## What is an Electric Current?

### Moving electric charges; measures the amount of charge passing a given point every second

3

## What does a battery do in a circuit?

### It supplies the potential difference (voltage) needed to maintain a continuous flow of charge

4

## What path does an electric charge take in a circuit?

### Positive to negative

5

## What is a Resistor?

### Device whose function is to oppose the current of a circuit

6

## What is an Ammeter?

### Device that measures the current; used in series with a circuit

7

## What is a Voltmeter?

### Device that measures potential difference; used in parallel to a circuit

8

## Is there an observable difference in readings of an ammeter when it is moved to a different location?

### No

9

## Is there an observable difference in readings of an voltmeter when it is moved to a different location?

### No

10

## What differences in readings of a ammeter/voltmeter are observable?

### Difference in emf across the terminals of a battery

11

## What is Electromotive Force (emf)?

###
Potential difference; voltage

Units: Volts

12

## What is a Circuit?

### A complete loop/circle of wire that allows for continuous flow of charge

13

## What is Terminal emf?

### First emf reflects the work done by the battery to move more change through the circuit and across terminals of the battery; total voltage; also known as internal emf

14

## What is Resistance?

### Electrical friction caused by the interaction of flowing electrons and molecules of a wire

15

## What is resistance dependent on?

### Temperature

16

## What does an increase in temperature do to the resistance of a circuit?

### Increases the current flow

17

## What is Ohm's Law?

### If temperature is constant, as the voltage increases, a greater flow of current will be observed; direct relationship between voltage and current

18

## What is the equation for resistance? (aka Ohm's Law)

###
R=V/I or V=IR

Units: ohms (Ω)

19

## What is the slope of a voltage vs current graph represent?

###
slope=resistance

R=V/I

20

## What is Resistivity?

### Measure of resisting power of a certain material to the flow of an electric current (ρ)

21

## What is the equation for resistivity?

###
R=ρL/A

L=length of wire

A=area of cross section

Units (ρ)=Ω*m

22

## What happens if a wire has a smaller cross section area? (R=ρL/A)

### The resistance of the wire will increase

23

## What happens if the length of the wire increases? (R=ρL/A)

### The resistance of the wire will increase

24

## What is the equation for the total power of a circuit?

###
P=ΔVI

Units: Watts (W)

25

## What is equation for electrical energy?

###
E=Pt or E=WIt or E=I^2Rt

Units: Joules (J)

26

## What is a Series Circuit?

### A circuit consisting of two or more resistors sequentially placed within one circuit

27

## What will happen if there is a break (ie. light bulb goes out) in a series circuit?

### The entire circuit will shut down; the continuous path is broken

28

## Is the current of a series circuit the same or different throughout the circuit?

### The current is the same because there is only one circuit

29

## Is the terminal emf (or voltage) of a series circuit the same or different throughout the circuit?

### The voltage is different; it is equal to the sum of all the emf's across all of the resistors

30

## Where is there potential drop in a circuit?

### Across each resistor

31

## What is Potential Drop?

### The amount of voltage loss that occurs through all or part of a circuit due to resistance; also known as voltage drop

32

## What will happen to a series circuit if more resistors are added?

### The electric current will decrease by increasing the resistance of the current, if the voltage is the same; as resistance increases, current decreases

33

## What is the equation for the current of a series circuit?

###
I(total)=I1=I2=I3

Current is the same throughout

34

## What is the equation for the voltage of a series circuit?

###
V(total)=V1+V2+V3

IR(total)=IR1+IR2+IR3

Voltage is different/shared

35

## What is the equation for the resistance of a series circuit?

### R(total)=R1+R2+R3

36

## What is a Parallel Circuit?

### A circuit consisting of two or more resistors connected across each other to a common point of potential difference

37

## What happens if there is a break (ie. light bulb going out) in a parallel circuit?

### The circuit does not go out because the current can flow to through the other path

38

## Is the voltage of a parallel circuit the same or different throughout the circuit?

### Same because each resistor is connected at a common potential point; voltage across each resistor is equal to the source voltage

39

## What will happen in a parallel circuit if more resistors are added?

### Will increase the effective circuit current by decreasing the circuit resistance; as resistance decreases, current increases

40

## What is the equation for the voltage of a parallel circuit?

###
V(total)=V1=V2=V3

Voltage is the same throughout

41

## What is the equation for the current of a parallel circuit?

###
I(total)=I1+I2+I3

V/R(total)=V/R1+V/R2+V/R3

Current is different/shared

42

## What is the equation for the resistance of a parallel circuit?

### 1/R(total)=1/R1+1/R2+1/R3

43

## What are Kirchhoff's Circuit Laws (2)?

### Junction Rule (current) and Loop Rule (voltage)

44

## What is the Junction Rule?

### The sum of currents flowing into a branch must equal the sum of currents leaving

45

## What is the Loop Rule?

### The sum of all emfs around a loop is equal to the sum of the potential drops around the loop

46

## Where should an ammeter be placed in a circuit?

### In series, right before or after the given resistor; an ammeter measures the current

47