Electricity Flashcards
how can insulators be charged by?
Friction
can cause both insulators to become charged when they move relative to each other
one positively charged
other one negatively charged
how is charging caused by gain or loss of electrons?
when atom loses an electron - more protons and more positively charged
when atom gains an electron - more electrons than proton more negatively charged
what is an electrostatic conductor?
material able to disperse electrons easily like Gold or Aluminium
what can be caused due to sparking?
fire
how can the risk of sparking be eliminated?
by earthing
connected to the earth then sparking doesn’t take place
What is the formula for Charge in terms of current and time?
Q= I T
How is a voltmeter connected?
in parallel
How is an ammeter connected?
series
How to calculate voltage in terms of resistance and current?
V = I R
what happens when the temperature of the filament increases?
resistance also increases
what is a thermistor?
resistance dependent on temp
eg: NTC - as temp increases the resistance decreases
what is a LDR?
resistor depending on the light intensity
more Li resistance decreases
what is an ideal diode?
allows current to move in one direction
what is the current in series circuit?
all the same
what is the total voltage in a series?
the sum of all volatges of each component
what is the total resistance?
sum of all resistances
what is the voltage in a parallel?
all the same
what is the total current in parallel?
sum of all current across components
what is the 1 / total resistance in parallel?
sum of recipricol of all resistances
energy transfer = power * ?
time
e = ivt
