Topic 2a- Circuits Flashcards
Voltmeters are always connected ________ .
in parallel.
Ammeters are always connected _________ .
in series.
Voltmeters measure…
potential difference.
Ammeters measure…
current.
What is current?
The rate of flow of charge.
What is the equation for charge flow (in coulombs)?
Q=It Charge flow (C)= current (A) x time (s)
What is potential difference?
The driving force that pushes a charge round a complete circuit.
What is resistance?
Anything in the circuit which reduces the flow of current.
What is the equation for potential difference (that links to resistance and current)?
V=IR
potential difference(V)= current(A) x resistance(Ω)
At a constant temperature, the current flowing through an ohmic conductor is…
…directly proportional to the potential difference across it.
What is Ohm’s law?
The voltage across a conductor is directly proportional to the current flowing through it, provided all physical conditions, such as temperature, remain constant.
What are I-V graphs?
Graphs that show current-potential difference.
What does a curved line on an I-V graph mean?
That the component is non-linear.
What does a straight line on an I-V graph mean?
That the component is linear.
What relationship do diodes have with current?
Will only really let current flow one way through it, otherwise the resistance is very high.
