Chapter 4 -Electricity Flashcards
(33 cards)
do like charges attract or repel?
repel
Resistance equation(involving current and potential difference)
Resistance= potential difference/current
R=V/I
How does current behave in a series circuit?
It stays the same
How does the PD behave in a series circuit?
Pd across components add up to pd across supply
how does current behave in parallel circuits?
The current in branches add up to the current in the supply.
How does PD behave in a parallel circuit?
The PD across the supply is the same as the PD across each branch.
what is PD?
a measure of the energy given to the charge carriers in a circuit
(basically energy from the supply)
What is electric current?
The flow of charge
or(Moving electric charges, eg electrons moving through a metal wire.)
List the I-v Characteristics of a filament bulb
•As current increases so does resistance
•This means less current can flow per unit PD.
•Therefore I-V graph gets shallower
What is electricity?
The flow of electrons along a wire.
Current Equation( involving time and charge)
Current =charge/ time
I=Q/t
I= Current(Amps, A)
Q= Charge( Coulombs, C)
t=time(in seconds, S)
What is Static Electricity?
An electric Charge that builds up on the surface of an insulator.
Example: A plastic comb
List an ohmic Conductors I-V characteristics
•The current and PD are directly proportional given there is no change in heat
•Constant
•The I-V graph has a straight line
True of false? All components in series will have the same size current flowing through them
True
How do you work out the total resistance of a series circuit?
By adding up the resistance of each component in the circuit
or
R=V/I
do ammeters need to be connected in series or parallel?
series
do voltmeters need to be connected in series or parallel?
Parellel
What two things affect the size of a current?
•Resistance
•Potential Difference
If resistance increases what happens to the current?
It decreases(because less current can flow per second)
If the potential difference is increased what happens to the current?
It increases
the longer the wire the…….. the resistance
Higher
What is Power
Power
Power (P) is the rate of energy transfer to a component.
what happens if you rub a polythene rod with a dry cloth?
The electrons from the dry cloth are transferred to the rod making the rod negatively charged
What happens if a Perspex rod is rubbed with a dry cloth?
The Perspex rod transfers electrons from the rod to the cloth making the cloth negatively charged and the rod positively charged.
