2. Electricity Flashcards
What is the charge of an electron
-1.6x10^ -19 C
What are the four laws of electrostatics?
- Opposites attract, like repel
- Charge is usually distributed evenly around objects
- Charges concentrate around sharp corners
- Coulomb’s law
Explain the difference between mA and mAs
mA=The total amount of electrons from the cathode to the anode per second
mAs= The total number of x rays produced in a beam
Define effective value (RMS)
The value of the constant DC current that would generate the same amount of heat in an AC current?
Is there potential energy in insulators?
No, bc the current should not flow through, there are no electrons in the conduction band
Give 3 examples of conductors
- Copper
- Gold
- Silver
What are the factors affecting resistance? Explain.
- Materials: Whether its a conductor or resistor
- Area: As the area increases, R decreases (2xA=1/2 R)
- Length: As the length increases, so does R bc there is more to pass by
- Temp:
-An increase in T in conductor=Increased R
-An increase in T in insulator=Decreased R
In which circuit does Voltage drop as it goes through resistors?
Series
What are three examples of circuit safety?
- Grounding
- Fuses and Circuit breakers
- GFCI
Define power:
The rate at which work is being done
When energy is needed to overcome resistance, in which way does energy go down?
Voltage goes down, we see it in the form of heat in series circuits
What are the 3 uses of capacitators?
- Waveform smoothing
- Electrical storage
- Timer circuits