electricity Flashcards
What equation links charge current and time and what are its units
Q=IT
charge flow coulombs C
Current Amps A
Time Seconds S
What equation links potential difference current and resistance and what are its units
V=IR
potential difference Volts V
Current Amps A
Resistance Ohms Ω
What equation links Energy transferred power and time and what are its units
E=PT
Energy transferred Joules J
Power Watts W
Time Seconds S
What equation links potential difference charge flow and Energy transferred and what are its units
E=QV
Energy transferred Joules J
Potential difference Volts V
Charge flow coulombs C
What equation links Power potential difference and current and what are its units
P=VI
Power watts W
Potential difference Volts V
Current Amps A
Will electrical current flow around an open circuit
False current only flows around a closed circuit if there’s a potential difference
What is resistance
Resistance is anything that slows down a force
Will a large resistance cause a large current
False
The greater the resistance across a component the smaller the current.
They re inversely proportional.(ohms law)
How does current behave in a series circuit
The current is the same all round the circuit.
How does current behave in a parallel circuit
It splits at all the junctions and combines later
How does potential difference behave in a parallel circuit
Each branch has the same Potential difference
Why does the national grid use high voltage transmission lines
High voltage causes electricity to be transmitted efficiently, safely, and with minimal energy loss, reducing costs
what do step up transformers do
increase voltage and decrease current
what do step down transformers do
Decrease voltage for safe use in houses
How does static charge build up
Friction causes electrons to transfer making objects positively or negatively charged
What happens when two charged objects are brought close together
Like charges repel
Opposite charges attracts
What do electric field lines show
Direction of force on a positive charge the closer the lines the stronger the fields
What does an Ohmic conductor graph look like
A line that goes straight through the origin.
current and voltage are directly proportional. And it has a constant resistance
What does an Filament lamp graph look like and what are its observations
S shaped curve steeper at low voltage and flattens at high voltage.
As current increases temp increases so the resistance also increase
What does an Diode graph look like and what are its observations
Flat towards the negative x axis and steepens on the positive.
current only flows in one direction has a high resistance in reverse direction one side biased
What does an thermistor graph look like and what are its observations
A downward curve showing resistance decreases as temp increases.
As temp decreases resistance increases inversely proportional
What does an LDR graph look like and what are its observations
Downward curve showing resistance decreases as light intensity increases
What are blue brown and green wires
Blue neutral wire
Brown live
Green earth
Why does a balloon stick to a wall after being rubbed on hair
Balloon gains electrons making it negatively charged
