3.2 - Circuits Flashcards
what is an RC circuit
a circuit with a resistor and a capacitor
which fields have a short range
electrostatic, magnetic and nuclear
draw a Vt graph of a capacitor charging and discharging
see book
what is the time constant for an RC circuit
the time to increase the charge stored in the capacitor by 63% of the difference between initial charge and full charge, or the time taken to discharge the
capacitor to 37% of initial charge.
approximately how long does it take for an uncharged capacitor in an RC circuit to be fully charged
5t
approximately how long does it take for a fully charged capacitor in an RC circuit to be fully discharged
5t
what is capacitive reactance
the opposition of a capacitor to changing current measured in ohms
what is meant by growth
when the induced emf opposes an increase in current
what is meant by decay
when an induced emf opposes a decrease in current
explain the self inductance of a coil
when a changing current flows through a coil of wire, a changing magnetic field is induced around it. The changing magnetic field which is created always opposes the change in current which created in the first place.
state Lenz’s law
an induced electric current flows in a direction such that the current opposes the change that induced it
define inductance
a property of an electric circuit by which an electromotive force (emf) is induced in it by a variation of current
define inductance
a property of an electric circuit by which an electromotive force is induced in it by a variation of current
define back emf
the electromotive force that opposes the change in current which induced it
where is energy stored by an inductor
in the magnetic field around the current carrying inductor
