The fundamentals of electricity Flashcards
define electrostatics, give an example of this in real life.
the generation of static electricity from the result of charged (bodies) electrons.
i.e rubbing a cloth against a rod.
The rubbing action causes the rod to lose or gain electrons. If the rod loses electrons it becomes +ve and if it gains electrons it becomes -ve
what is 1 coulomb?
approx 6 x 10^18
How can dosimetry be calculated?
through how many electrons are liberated.
Define what an electric field is and what represents it
An electric field is an area where an electric charge will experience force which is represented by lines of force.
Shape can influence concentration of electrons, can you give an example.
Objects with sharp ends will have an increased concentration of electrons
Define electricity
The flow of free electrons within a conductor.
What is Ohm’s law calculation
voltage = current x resistance
Define Ohm’s law
The law states that current flowing through a conductor is directly proportional to the voltage and inversely proportional to resistance.
What is potential difference (PD)
Referred to as volts (V) is a measure of the electric potential energy per unit charge in an electrical circuit.
What is the Potential difference (PD) equation definition
1 Volt is the PD at a point if 1 Joule of work is done in moving 1 Coulomb of charge from one point to another (Joule – unit of energy)
Provide a medical example of when a low potential difference is required
chest imaging (10kV)
Provide a medical example of when a high potential difference is required
When the patient is thicc or when we need to penetrate deeper i.e. pelvic imaging (120kV)
Define current and what it is measured in
measured in amps and is the flow of charge in a conductor
Define resistance and what it is measured in
measured in Ohms and is the measure of the opposite flow of electrons to the current flow
Insulators are … resistance
conductors are … resistance
high
low
