Current, Charge and Voltage Flashcards
What is current
Current is the rate of flow of charge
How can you measure current
You can measure current using an ammeter placed in series
What is conventional current flow
The flow of current from positive to negative so in only one direction
What is potential difference
The work done per unit charge
How to measure the potential difference
Place a voltmeter in parallel to the component you are investigating
What is the mean drift velocity
The average velocity of charge carriers. Charge carriers are the charged particles the current flows which are free electrons (Any particle that has a charge is a charge carrier)
Mean drift velocity equation
I=nqva
(Current= number density x charge x mean drift velocity x cross sectional area
What is the elementary charge
“e” this is 1.60 x 10^-19
When an ammeter is placed in a circuit should it have a low or high resistance and why?
It should have the lowest resistance in order to reduce the effect that they have on current ( A resistor restricts the flow of current through resistance )
Whats the difference between conventional flow and electron flow in a metal wire
Conventional flow is the flow of current from the positive to the negative terminal. Electron flow however is the flow of electrons form the negative to positive terminal terminal.
Similarities and differences between electric current in a metal wire and in an ionic solution?
In the liquids the electric current is not a flow of electrons but a flow of ions whereas in a metal wire it is a flow of electrons
Why are metals good conductors
Metals have a very high electron density (n) whereas semiconductors and insulators are much lower
