Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physics > Electricity > Flashcards

Electricity Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

Conductors

A
  • A conductor is a material that allows the flow of electrical charge.
  • Good conductors have a larger amount of free charge carriers to carry a current.
  • An insulator is the opposite, as it does not allow the flow of electrical charge easily.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Conventional Current

A

The flow from positive to negative, used to describe the direction of current in a circuit.
(Negative to positive is called electron flow)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Electrolytes

A
  • Substances that contain ions that when dissolved in a solution,
  • act as charge carriers and allow current to flow.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Kirchhoff’s First Law

A
  • Consequence of the conservation of charge.
  • The total current entering a junction must equal the total current leaving it.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Mean Drift Velocity

A
  • The average velocity of an electron passing through an object.
  • It is proportional to the current, and inversely proportional to the number of
    charge carriers and the cross-sectional area of the object.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Semiconductors

A
  • A material that has the ability to change its number of charge carriers, and thus its ability to conduct electricity
  • Examples include light-dependent resistors and thermistors.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Diode

A
  • A diode is a component that allows current to flow in one direction only.
  • In the correct direction, diodes have a threshold voltage (typically 0.6 V) above which current can flow.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Electromotive Force

A

The energy supplied by a source per unit charge passing through the source, measured in volts.

(Chemical to electrical)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Filament Lamp

A
  • A bulb consists of a metal filament that heats up and glows to produce light.
  • As the filament’s temperature increases, its resistance also increases.
  • This occurs because the metal ions vibrate more, making it harder for the charge carriers to pass through.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Kilowatt-Hour

A

A unit of electrical energy. It is usually used to measure domestic power consumption.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Light-Dependent Resistor

A

A light sensitive semiconductor whose resistance
increases when light intensity decreases.

(Light energy excites electrons and move to Valence bands)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Negative Temperature Coefficient Thermistor

A

This means that the resistance decreases
as the temperature goes up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Ohmic Conductor

A
  • An ohmic conductor follows Ohm’s Law.
  • The current flow is directly proportional to the potential difference across it, when under constant physical conditions.
  • The constant of proportionality is the resistance.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Potential Difference

A
  • The electrical potential difference between two points in a circuit is the difference in electrical potential.
  • electrical energy 𝑊 (Joules) transferred
    into other forms when a unit charge 𝑄 (Coulomb) passes between two points in a circuit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Resistivity

A
  • Resistivity is the resistance of a cube of unit length sides
  • It is proportional to the object’s resistance and cross-sectional area, and inversely proportional to the object’s length.
  • It is measured in Ohm metres.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Internal Resistance

A
  • The resistance to the flow of charge within a source is called internal resistance.
  • Internal resistance results in energy being dissipated within the source.
17
Q

Kirchhoff’s Second Law

A
  • A consequence of the conservation of energy.
  • The sum of the voltages in any closed loop must equal sum emf.
18
Q

Lost Volts

A
  • The difference between a source’s emf and the terminal voltage.
  • It is equal to the potential difference across the source’s internal resistance
19
Q

Potential Divider

A
  • A method of splitting a potential difference by connecting two resistors in series is called a potential divider.
  • The total potential difference is split in the ratio of their resistances.
20
Q

Resistors in Parallel

A
  • The potential difference across resistors connected in parallel is identical for each resistor.
  • The current is split between the resistors.
  • The total resistance is equal to the inverse of the sum of the inverses of the resistances of the resistors.
21
Q

Resistors in Series

A
  • The current through resistors connected in series is identical for each resistor.
  • The potential difference is split in the ratio of their resistances.
  • The total resistance is equal to the sum of the resistances of the resistors.
22
Q

Terminal PD

A
  • The potential difference across the terminals of a power source is called the terminal voltage.
  • It is equal to the source’s electromotive force (emf) minus any voltage drop over the source’s internal resistance.
23
Q

Cathode

A

A negatively charged electrode
(Anode being positive)

24
Q

Kilowatt-hour

A
  • 1 kWh equals 3.6 million joules. kWh is used due to the large electricity usage in households.
  • To calculate the energy usage of an appliance, multiply its power by the time used.
  • The cost is calculated by multiplying the number of units used by the price per unit.
25
Q

Series Circuit

A
  • In series circuits, the current is the same at all points.
  • The e.m.f. is split between components by Kirchhoff’s 2nd law, so ΣV = V total . Voltage splits proportionally to resistance, as V = IR.”
26
Q

Parallel circuit

A

In parallel circuits, current is split at each junction, so ΣI = I total . There’s the same potential difference (p.d.) across all components as the p.d. across each branch equals the e.m.f.

27
Q

Super conductor

A
  • Superconductors exhibit zero resistivity at or below a critical transition temperature, which varies by material.
  • Many materials become superconducting at extremely low temperatures, around 10 K (-260°C).
28
Q

How to analyse circuits

A

-Calculate total resistance
-Calculate total current (emf ÷ R total)
-Calculate P.D of each component
-Calculate current of each branch (emf ÷ R total of branch)

29
Q

Electron gun

A
  • Creates a beam of electrons with a specific kinetic energy by applying an accelerating potential difference between an anode and a hot filament.
  • eV = KE
30
Q

Number density

A

Number of charge carriers per unit volume

31
Q

Resistance

A

Measure of how difficult it is for charge to travel through a material.

32
Q

Mains

A
  • AC (alternating voltage)
  • 50 Hz 230 V
  • AC to DC formula is amplitude ÷ √2

Physics (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions