Unit 1: Electricity

Flashcards for remembering key ideas behind electricity such as current, power, resistance, series & parallel circuits, resistivity, potiental dividers, alternating current and oscilloscopes.

?
Current (I)
The rate of flow of charge (A, Amperes) I= Q / t
1 of 18
Potential Difference (V)
PD= WD (J) / Q (C)
2 of 18
Resistance (Ω)
R= V / I
3 of 18
A Volt (1V) is...
a Joule per Coulomb (1J/C)
4 of 18
Conventional current goes from....
Positive to negative. Technically this is wrong, but accepted.
5 of 18
Ohm's Law...
...states as long as temperature and physical conditions stay the same. Current is directly proportional to Potential Difference.
6 of 18
Conductance (G) is...
Reciprocal of resistance, measured in Siemens (S). G= I / V
7 of 18
A Variable Resistor....
changes the potential difference and current. (Variable power supply will also do this)
8 of 18
A < 1 > must be connected in series. A < 2 > must be connected in parallel
Ammeter in series. Voltmeter in parallel.
9 of 18
If the gradient on a I/V graph gets steeper...
...then the resistance must be increasing. (And vice versa)
10 of 18
Diodes...
are semi-conductors only allow charge one way, forward bias. (Most have a 0.6V threshold potiental)
11 of 18
A potentiometer...
allows a change of volts supplied from the battery source.
12 of 18
Resistivity (ρ, Ohms M-1)...
ρ = A R / l
13 of 18
Conductivity...
..is simply the inverse of Resistivity (G) = 1 / ρ
14 of 18
Power is....
P= I V Note: 1 Watt= 1 Joule per 1 second
15 of 18
Passive Transducers (Resistive Transducers)...
are things like LDRs, Thermistors, Strain Gauges & Moisture Detectors. They change resistance according to environmental factors.
16 of 18
A Thermistor...
has a negative temperature coefficient. This is because as it warms up more energy carriers become available to carry charge.
17 of 18
Potential Divider (in words..)
is used to change PD. This works by using 2 resistors in series, the fractional resistance of one resistor out of both is the way of spliting the overall PD.
18 of 18

Other cards in this set

Card 2

Front

PD= WD (J) / Q (C)

Back

Potential Difference (V)

Card 3

Front

R= V / I

Back

Preview of the back of card 3

Card 4

Front

a Joule per Coulomb (1J/C)

Back

Preview of the back of card 4

Card 5

Front

Positive to negative. Technically this is wrong, but accepted.

Back

Preview of the back of card 5
View more cards

Comments

No comments have yet been made

Similar Physics resources:

See all Physics resources »See all D.C. Electricity resources »