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

charge equation

A

current x time

Q = It

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

potential difference

A

current x resistance

V = IR

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

power with v and i

A

potential difference x current

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

power with i and r

A

current x resistance

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

energy transferred

A

power x time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

energy transferred with q and v

A

charge flow x potential difference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Series Circuits

A

Components that are connected one after another on the same loop of the circuit are connected in series

The sum of all the potential differences across the components in a series circuit is equal to the total potential difference across the power supply.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Two lamps connected in series

A

If one lamp breaks, the other lamp will not light.

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

Parallel Circuits

A
  • Components that are connected on separate loops are connected in parallel.
  • The current is shared between each component connected in parallel.
  • The total amount of current flowing into the junction, or split, is equal to the total current flowing out.
  • The current is described as being conserved.
  • For a parallel circuit the current from the electrical supply is greater than the current in each branch. The sum of all the current in every branch is equal to the current from the electrical supply.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Two lamps connected in parallel

A

If one lamp breaks, the other lamp will still light.

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

AC

A

If the current constantly changes direction it is called alternating current, or AC. Mains electricity is an AC supply. The UK mains supply is about 230 V. It has a frequency of 50 Hz, which means that it changes direction and back again 50 times a second.

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

DC

A

If the current flows in only one direction it is called direct current, or DC. Batteries and solar cells supply DC electricity. A typical battery may supply 1.5 V.

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

how to get electrocuted

A 
touching frayed electrical cables
long or overheating cables
damaged or incorrectly wired plugs
allowing water or wet objects to enter plug sockets or touch frayed cables
pushing metal objects into plug sockets
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

BRown

A

Live Is held at a voltage of 230 V and provides the current - Goes Right

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

BLue

A

Neutral Completes the circuit - Goes Left

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Green and yellow stripes

A

Earth A safety wire to stop the appliance becoming live

17
Q

Fuse

A

The fuse breaks the circuit if a fault in an appliance causes too much current to flow. This protects the wiring and the appliance if something goes wrong. The fuse contains a piece of wire that melts easily. If the current going through the fuse is too great, the wire heats up until it melts and breaks the circuit.

18
Q

Electric current is

A

the rate of flow of electric charge.

19
Q

How does electricity pass through metallic conductors

A

Electricity passes through metallic conductors as a flow of negatively charged electrons. The electrons are free to move from one atom to another. We call them a sea of delocalised electrons.

20
Q

Voltmeters

A

Measuring potential difference (voltage)
Potential difference is measured in volts, V
the potential difference across a component in a circuit is measured using a voltmeter
the voltmeter must be connected in parallel with the component

21
Q

Ammeter

A

Measuring current
current is measured in amperes (amperes is often abbreviated to amps or A)
the current flowing through a component in a circuit is measured using an ammeter
the ammeter must be connected in series with the component

22
Q

Resistance in a wire

A

The resistance in a wire increases as:

the length of the wire increases
the thickness of the wire decreases

23
Q

Resistance of a long wire

A

The resistance of a long wire is greater than the resistance of a short wire because electrons collide with more ions as they pass through. The relationship between resistance and wire length is proportional.

24
Q

Why is there resistance in a wire ?

A

An electric current flows when electrons move through a conductor, such as a metal wire. The moving electrons can collide with the ions in the metal. This makes it more difficult for the current to flow, and causes resistance.

25
Q

Resistance of a wire when it is thin and thick

A

The resistance of a thin wire is greater than the resistance of a thick wire because a thin wire has fewer electrons to carry the current. The relationship between resistance and the area of the cross section of a wire is inversely proportional.

26
Q

What is a resistor ?

A

A resistor is an electrical component that restricts the flow of electric current.

27
Q

Ohms Law

A

The current flowing through a resistor at a constant temperature is directly proportional to the potential difference across it.

28
Q

Filament Lamp

A

A filament lamp is a common type of light bulb. It contains a thin coil of wire called the filament. This heats up when an electric current passes through it, and produces light as a result.`

29
Q

Diodes

A

Diodes are electronic components which can be used to regulate the potential difference in circuits and to make logic gates.

30
Q

LEDs

A

Light-emitting diodes (LEDs) and lamps produce light when a current flows through them in the forward direction.

31
Q

Thermistors

A

Thermistors are used as temperature sensors, for example, in fire alarms. In the most common type of thermistor, the resistance decreases as the temperature increases:

at low temperatures, the resistance of a thermistor is high and little current can flow through them
at high temperatures, the resistance of a thermistor is low and more current can flow through them

32
Q

LDRs

A

LDRs (light-dependent resistors) are used to detect light levels, for example, in automatic security lights. Their resistance decreases as the light intensity increases:

in the dark and at low light levels, the resistance of an LDR is high and little current can flow through it
in bright light, the resistance of an LDR is low and more current can flow through it

33
Q

Static Electricity on a carpet

A

The carpet is covered with electrons
As the man walks, he picks up electric charges
When they shake hands the electricity discharges
through the woman, giving her a shock

34
Q

Dangers of Static Electricity

A

It is dangerous when there are flammable gases or a high concentration of oxygen. A spark could ignite the gases and cause an explosion.

It is dangerous when you touch something with a large electric charge on it. The charge will flow through your body causing an electric shock. This could cause burns or even stop your heart. A person could die from an electric shock.

Refuelling aircrafts and tankers also poses a particular danger. If the fuel passing along the hose to the vehicle was allowed to build up a static charge, a resulting spark might ignite the fuel. The hoses are earthed to stop this occurring.

Physics (10 decks)

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