voltage & amps Flashcards
The size of the electric current is the rate of flow of _________.
electrical charge.
Current is equal to _____ divided by time.
charge
units for charge
coulombs
a current of of 1 ampere =
1 coulomb of charge flowing per second
An electrical insulator has_______
no free electrons. No charges are free to move and carry a current.
Which charges are free to move in metals?
electrons
all ______ are electrical conductors
metals
The energy is transferred to the electrical components in a circuit when ____________________.
the charge carriers pass through them.
what is potential difference
it is the energy difference per unit charge between two points in a circuit
potential difference =
current x resistance
If the resistance is increased, the current will _______
decrease
If the potential difference is increased the current will _______.
increase.
An electric current will increase when the number of ohms ______.
decrease
On a current-voltage graph for a resistor, the slope of the graph is equal to _______.
1/resistance
Resistance is a measure of how difficult it is for ______ to flow through a component.
current
what is a rectifier ?
A component that turns an alternating current (repeatedly changes direction) into a direct current (one direction).
_______ act as rectifiers as they block the alternating current when it changes direction.
Diodes
of a rectifier, the output current is
direct current (DC)
of a rectifier, the input current is
alternating current (AC)
What is a thermistor ?
A component where resistance changes with its temperature.
What are light dependent resistor (LDR)s .
A component whose resistance changes with light intensity.
The current through an ohmic conductor (at a constant temperature) is _______.
directly proportional to the potential difference across the resistor.
In an Ohmic conductor, the resistance…
remains constant
R=
P÷I 2