Electricity Flashcards
(26 cards)
What is important about the valence shell?
The less electrons in the valence shell the more likely that the electron can be moved
what is electrostatic?
1) opposites attract
2) likes repel
What is electron current?
The flow of electrons from negative to positive. As one electron is added, it replaces and pushes out the next electron, and that one does the same and so on. The effect is instantaneous no matter the length of the conductor.
What is current?
the flow of electrons through a conductor. It’s unit of measure is amperes or amp expressed as I. Is the pushing force / moves the electrons through the circuit
what is voltage
The potential difference between positive and negative. It’s unit of measure is volt expressed as V.
What is resistance?
the opposition to current flow. It’s unit of measure is the ohm expressed as R
What is Ohm’s law?
The current in a circuit is directly proportional to the applied voltage and inversely proportional to the circuit resistance
What are the 4 requirements of a circuit?
1) Switch
2) power source
3) conductor (wires)
4) load (explosive)
what is a conductor?
Any material that will allow electrons to move within it freely
What is an insulator?
A material that does not allow the electrons to move within it freely
What does a capacitor do?
Store electrons (energy/power)
What will happen to batteries in series?
increase voltage but the amperage will remain the same
What will happen to batteries in parallel?
increase amperage but voltage will remain the same
What factors effect resistance?
The conductors length, diameter, material, and temperature
What are the 4 requirements for arming and fuzzing circuits?
SPICE
1) S- switch
2) P- power source
3) I- initiator
4) C- conductor
E-explosive
What are the laws of series circuits?
The sum of the individual voltage drops around a series circuit equals the applied voltage, current has the same value at any point within a series circuit, the sum of the individual resistances within a series circuit equals the total resistance of that circuit, to add the total resistance R1=R1+R2
Wha are the laws of parallel circuits?
The voltage is the same across each branch of the circuit, total current is equal to the sum of the individual branch currents, total resistance is always less or approximately equal to the value of the smallest resistive branch. Rt=R1+R2+R3
Explain switch contacts
When at rest with no outside influence:
Common - regardless of the switch, will always be used
Normally open (NO)
Normally closed (NC)
What are relays?
Electromagnetic switch
What are some of the dangers of relays?
Battery decay
Cutting the wrong wire
Anti-disturbance (caused by a weak battery)
What causes a collapsing circuit to function?
Battery decay
Cutting the wrong wire
Anti-disturbance
What causes movement of the contacts in a relay?
The energizing / de-energizing of the coil. The relay is an electromagnetic switch
Explain the voltage in a series circuit?
It will change across each load in accordance with the amount of resistance
Explain the voltage in a parallel circuit?
The voltage stays the same across all paths in parallel
