Week 10 Flashcards
Static Electricity:
when materials are rubbed together a force is created that attracts or repels objects, without contact
I = current, SI unit - ?
ampere
direction of current and flow of e:
By custom the direction of the current is taken to be in the direction of flow of positive charge.
Thus, a flow of electrons to the right corresponds to a **current *to the left.
Kirchhoff’s law of currents or Kirchhoff’s first law:
sum of all the currents coming into a point equals to the sum of all the currents leaving that point
algebraic sum of the potential changes around a loop
is zero
For any number of series resistors:
and
For any number of resistors in parallel:
Rs = …
1/Rs = …
the most important factors in determining the effect of electric current passing through the human body are (3):
• the amount of current passing through the body,
• the path taken and the
• duration of the current flow.
shape of the ECG/EKG demonstrates:
when the activity of the heart is changing
With recording site,
The size of the ECG/EKG change, as does the shape of the signals
P wave corresponds to:
initial contraction of the atria
QRS complex corresponds to:
relaxation of the atria and initiation of ventricular contraction
T wave corresponds to
ventricular relaxation
ECG/EKG monitoring, which simply checks whether the heart is beating or not, uses electrodes placed in which plane?
FRONTAL
To diagnose malfunctions of the heart, the ECG/EKG is recorded from which plane.
FROM BOTH FRONTAL AND TRANSVERSE PLANES
Bipolar leads and why are they bipolar?
Leads I, II and III are referred to as bipolar leads.
This is because the measured signal is the difference in potential between two electrodes.
Unipolar measurements and how are they made, and in which plane?
aVR, aVL, aVF (augmented vector right, left, and foot)
Made by recording the potential at one electrode with respect to the average of the other two potentials
The transverse plane ECG/EKG is recorded unipolarly.
Charge:
1.602 x 10-19
independent of charge type (+ or -)
conservation of charge => net charge in a closed system is conserved
Coulomb’s Law, magnitude of the F that 2 objects exert on each other is:
linearly proportional to the net charge on each object
inversely proportional to the square of the distance between them
k = 8.988x109 Nm2C-2
E = electric field, SI?
N/C => how much F a +1C charge would experience
E = F/q = kQ/r2
Work is accomplished on an object if:
a force is exerted on the object, and the object moves in the direction of the force.
