2.3 dc circuits Flashcards
how to measure I of a circuit
ammeter connected in series w he component
what is a diode
a component that only allows current to flow in one direction
unless stated in question, should you assume that V have zero resistance or infinite R
infinite.
current takes path of least resistance so if voltmeter has infinite R, when applied in parallel to the appliance, no current will flow through it and all the current will flow through the appliance.
what is a light dependent resistor - LDR
a semi conductor that is sensitive to light
as the light intensity increases its resistance decreases
how do you find the total resistance in a series circuit
Rtotal = R1 + R2 + R3 + ….
how does the current vary between each component of a series circuit
through all components its the same. does not vary
is the current in parallel components the same
no each branch of the circuit can have diff currents through them
Kirchhoff’s first law
current law
- all of the current going into the junction is equal to the current laving the junction
Kirchhoff’s second law
pd law
- for any path of a circuit, the sum of all the pd must equal the total emf of the circuit
what is the purpose of a potential divider
to provide a variable pd or to provide a constant specific pd
what i emf
electromotive force - the electrical energy transferred by a power supply per unit charge
