Electricity Flashcards
What is alternating current
The ac current is a current which constantly changes size and direction with time
What is direct current
Dc current is the current that flows in one direction only
How do you calaculate the frequency of one wave
T=1/f
What is the rms voltage (Vrms)
The value of the direction voltage that produces the same power (heating effect) as the alternating voltage
Current definition and equation
True current is defined as the number of colombs of charge gap pass a point in 1 second or in one second
Q=It
What is the voltage
The energy transferred to each unit of charge
What is the power
The power is the electrical energy transferred every second
What is the emf
Is the energy supplied to each coulomb of charge that passes through the supply
Wheat is the capacitance
Is the ability of a component to store charge
Look at pg15
In an _______ atom the electrons occupy discrete ___________
In an isolated atome the electrons occupy discrete energy levels
Pg 20 for diagram
What can solids be categorised to
Conductors, semiconductors and insulators
What is doping
Is the addition of a very small amount of impurity to a pure semiconductor.
What can doping with specific impurities do
Increase the conductivity of a very semiconductor
3 key things you need to know about n-type
1.)When arsenic is added from groups it had 5 outer electrons in the outer shell
2.) 4 electrons fill the valence band leaving one. Electron in the conduction band
3.) the electrons in the conduction band are free to move allowing more conduction
Look at notes pg 22-23
What does a forward bias do
Reduces the electric field I. The p-n junction
