Carsouel 1 Flashcards
what is the charge of a neutron
neutral
which parts of the atom can move
electrons
what direction does an ac current move
There’s not set direction so it could either be positive to negative or negative to positive
what is resistance
a force that counteracts the current
if you connect 2 resistors in series will the current be different or the same across the two
the same although the current is reduced
if you connect 2 resistors in parallel will the current be different or the same
same
what does EMF stand for
Electrical Motive Force (open circuit voltage of a battery)
what happens to the voltage of a battery when a load is connected to it
Reduces due to internal resistance of the battery
if current flows away from you what direction does the magnetic field flow
anti-clockwise
if you increase the current what happens to the magnetic field
increases
what happens to an iron bar if you wrap a coil of wire around it and apply voltage
it’s converted into an electronic magnet
why’s it good practice to have the earth wire as the longest wire within a plug
as if the other wires are pulled out it prevents you from getting a shock as the current would be carried through the earth wire
four steps to test for dead
- check voltage indicator for any faults
- prove the lights illuminate when voltage is applied
- test all possible combinations
- prove that the voltage detector can still detect voltage
why is it good practice to have the sheath pretruding beyond the collar of the gland
to prevent a short circuit being produced due to friction within the cores removing the insulation
how much voltage would be across 3 different components within a parallel circuit
they would all receive the same voltage
a battery has an open circuit voltage what is this known as
what is eddy currents
loops of electrical current induced in a conductor by a varying magnetic field
what is the rule for motors that gives the direction of current, field and motion
Left hand motor rule
every conductor has a resistivity what does this mean
the amount of resistance that is applied against the supply
two methods of increasing the output voltage of a generator
- speed
- number of coils
why do we step up the voltage to very high voltage on the national grid
to reduce their loses
what does RMS stand for
Root Mean Square
what is the principle of rms on ac systems
value of steady current
what is rectification
changing AC to DC
what does a diode do
only allows the flow of current in one direction only
what charge does the electron have
negative
what is static electricity
caused by friction positively or negatively charging a part of the body
difference between ac and dc
dc is a direct current
ac is an alternating current
difference between voltage and current
current is the flow of electrons throughout the circuit
voltage is the charge that the electrons have within them
what happens when you select ohms on a multimeter
the meter has become a power source
when you select amps what happens on a multimeter
the meter has low resistance
what happens when you select volts on a multimeter
the meter has high resistance
Tesla
density
weber
strength
henry
amount
what is the standard unit for a capacitor
Farad
three common uses of a capacitor
energy storage
power conditioning
signal processing
what is frequency
how many of those periods happen within a second
harmonised colours
brown black grey and blue as neutral
pre harmomised colours
what is emf
open circuit of a battery
