Electricity

Question 0

Conventional Current

Answer 0

Positive to negative

Question 1

Electron Flow

Answer 1

Negative to positive

Question 2

Electricity

Answer 2

An invisible force that can produce heat, light, motion by attraction or repulsion, and many other physical effects.

Question 3

Coulomb

Answer 3

Measure of charge

The charge transported by a constant current of one ampere in one second (1A/sec).

Question 4

Ampere

Answer 4

Measure of current (a)

Current is the movement of electrons

Question 5

Voltage

Answer 5

Or volt

Measure of potential difference.

Question 6

Ohm

Resistance is the opposition to the movement of electrons

Answer 6

Measure of resistance

Question 7

Coulomb’s Law

Answer 7

The force describing the electrostatic interaction between electrically charged particles separated by a distance.

Question 8

Resistance of a wire

Answer 8

4 things

1. Material
2. CSA
3. Length
4. Temperature

Question 9

Conductors

Answer 9

Produce low resistance

Silver, copper, 0.9% saline, other electrolyte solutions.

Question 10

Insulators

Answer 10

Produce high resistance

Glass, rubber, paper, air

Question 11

Semiconductors

Answer 11

Produce higher resistance then conductors but lower resistance then insulators

Carbon, germanium, silicon.

Question 12

DC Voltage

Answer 12

Flow of charge in one direction and the fixed polarity of the applied charge.

 Can be steady or vary in magnitude.

Question 13

AC Voltage

Answer 13

Polarity periodically reverses or alternates, flow of charge revere as the polarity changes

Varies in magnitude.

Question 14

Amplitude

Answer 14

The maximum absolute value reached by a voltage or current waveform

Question 15

Frequency

Answer 15

The number of waves that pass a fixed point per unit of time

Expressed in Hertz (Hz). One Hz is equal to one cycle per second
I.e. 60 Hz = 60 cycles/sec

Question 16

Electrical Interference

Answer 16

Common in OR

60 Hz

Question 17

AC > DC

Answer 17

Sustained at higher voltages over longer distances ( less voltage drop)

It can be stepped up or down with the use of transformers

It can power devices that require 120v to 240v

Question 18

OHM’s Law

Answer 18

I=V/R

Question 19

OHM’s Law and Perfusion

Answer 19

Effect= Cause/Opposition

Every conversion of energy from one form to another can be related to this equation.

Question 20

Hemodynamics

Answer 20

The physical factors that govern blood flow

Question 21

Poiseuille’s Law

Answer 21

R= Ln8/ pi*r^4

Describes the relationship between pressure, flow, and resistance for liquid flowing through a cylindrical tube.

Two assumptions

1. Radius is uniform
2. Flow is laminar

Question 22

Reynolds Number

Answer 22

Dimensionless quantity whose magnitude give s an indication of whether the flow is laminar or turbulent

Question 23

Laminar Flow

Answer 23

Re< 2000

Want laminar flow in perfusion

Question 24

Turbulent Flow

Answer 24

Re> 2500

Decrease flow rate

Cause air to come out of solution = BAD

Increase perfusion pressure at given flow rate

Question 25

Increase radius by 2x

Answer 25

Resistance= 1/16 R

Flow= 16Q

Question 26

Decrease radius by 1/2

Answer 26

Resistance= 16 R

Flow= 1/16Q

Question 27

For current to flow

Answer 27

1. A complete circuit is needed (a circle!)

2. A potential difference impressed across the circuit.

Question 28

Series Circuit

Answer 28

V(total)= V1 + V2 + V3….

I(total)= constant

R(total)= R1 + R2 + R3….