Electricity

Question 1

Conventional current is the movement of _____ charges.

Answer 1

positive

Question 2

Identify the following symbols:

Answer 2

• alternating current
• battery
• amplifier
• amplifier 2
• capacitor
• capacitor 2
• resistor
• resistor 2

Question 3

Identify the following symbols:

Answer 3

• inductor
• transformer
• circuit breaker
• fuse about to blow
• ground
• ground 2
• diode
• meter
• transistor
• rectifier
• wire

Question 4

Identify the following circuits:

Answer 4

open circuit

closed circuit

short circuit

Question 5

What is defined as the “flow of charges per unit time”?

Answer 5

current

Question 6

What does the symbol with “A”? represent?

Answer 6

ammeter

Question 7

Definition: potential difference which is the potential energy required to move a charge of one coulomb from point A to point B.

Answer 7

voltage

Question 8

What does the symbol with “V” indicate?

Answer 8

volt meter

Question 9

V = IR is known as what law?

Answer 9

Ohm’s Law

Question 10

Pressure (P) of voltage units:

Answer 10

dynes/cm²

Question 11

Flow of current units:

Answer 11

cm³/sec

Question 12

Heat flow (q) unit

Answer 12

Watts

Question 13

Solute concentration units?

Solute flow units?

Answer 13

mg/ml

mg/min

Question 14

The corollary to Ohm’s law is known as _____ law.

Answer 14

Ohm’s Law: V = IR

Darcy’s Law: P = QR

Question 15

What type of current varies around zero?

Answer 15

AC

Question 16

What depiction most represents the cardiovascular system?

Answer 16

DC + AC shows varying around a mean pressure

Question 17

This waveform depicts what?

Answer 17

arterial blood pressure waveform

Question 18

How is the mean pressure or the arterial pressure obtained?

Answer 18

Calculated as the area under the curve.

Question 19

frequency =

What are the units?

Answer 19

1/T

where T = period

Hertz

Question 20

If HR = 120 beats per minute, calculate frequency.

Answer 20

2 Hz

Question 21

Period (T) can also be measured on a graph as distance from ____________.

Answer 21

peak-to-peak

Question 22

Coulomb’s Law =

Answer 22

Force = Coulomb’s constant (charge strength/distance²)

Note:

• Opposite charges repel and vice-versa.
• If force is (+) = charges are repelled
• If force is (-) = charges attract

Question 23

Current produces a magnetic field.

If a current is moving in your direction, a magnetic field can be detected. How do you determine the direction of this field?

Answer 23

right hand rule

fingers move in the direction of curled fingers

Question 24

Current flows in direction of ___ charge flow.

Answer 24

positive

Question 25

Wires that are near each other, they will have magnetic field around them. Why will wires repel/attract?

Answer 25

Image 1 will repel because O and O. Image 2 will attract because O and X. O= current moving into the screen X = current popping out of screen

Question 26

Power =

Answer 26

P = IV "Pee" is equal to need "IV" * V = IR * P = IV

Question 27

The sum of the voltage variations around a loop is zero is known as what law? This best describes what type of circuit?

Answer 27

Kirchhoff's Voltage Law Series resistance

Question 28

The resistance in our arterial system are \_\_\_\_\_\_\_.

Answer 28

R1 + R2 + R3 = sum of precapillary arterioles, the only thing providing resistance in the arterial tree. We have some series circuits in our liver.

Question 29

Principle of an attenuator (weakener) What is the potential voltage measured in V2? What is the potential voltage measured in V3?

Answer 29

20% of V1 80% of V1

Question 30

If V1 = 10 V and each R = 1 ohm, What is the total current? What is the voltage drop across R₅? What is V₂ in the first picture? What is V₃?

Answer 30

R_T = 5x1ohm = 5ohm I = V/R_T = 10/5 = 2amps voltage drop across R₅ (V₂) = 2amps x 1ohm = **2V** = 0.2 x 10V V₃ = 2amps x 4ohm = **8V** = 0.8 x 10V

Question 31

The sum of all currents that converge on a node will be zero is known as what law?

Answer 31

Kirchhoff’s Current Law

Question 32

R_t =

Answer 32

Question 33

Arterial blood system is an example of what type of system?

Answer 33

DC + AC signal system

Question 34

Most circulating systems of the body (blood, pulmonary and lymphatic) are connected in \_\_\_\_\_\_.

Answer 34

parallel This ensure that the same force (pressure, voltage) is applied to each of the individual elements (end-organs) or the system.

Question 35

Physiologic resistance is usually related to the diameter of the conduits through which the "current" (blood, airway gases, etc.) flows. In the arterial blood system, these resistances are controlled by the ______ \_\_\_\_\_\_.

Answer 35

precapillary arterioles

Question 36

The "balance" equation: V = 0 when R1\*R4 = R2\* R3 (equal cross products)

Answer 36

Wheatstone Bridge It is a series and parallel combination of resistances that allows a variation in one of the impedances to alter the "balance" of the circuit.

Question 37

What type of circuit is analogous to the vascular system?

Answer 37

parallel

Question 38

If V1 = 10V and each R = 2ohm, what is the total current?

Answer 38

1/RT = 1/R1 + 1/R2 + 1/R3 = ½ + ½ + ½ =1.5 RT = 1/1.5 = 0.666ohm I = V/R = 10/0.666 = 15amps Note: Rt will be less than the smallest resistor.

Question 39

What is the voltage across A → B? This bridge is commonly used in _____ \_\_\_\_.

Answer 39

0 pressure transducers

Question 40

The ratio of the change in an electric charge in a system to the corresponding change in its electric potential.

Answer 40

capacitance or, physiological “compliance”

Question 41

The property of a conductor by which a change in current which induces a voltage (electromotive force) in both itself and any nearby via \_\_\_\_\_\_'s Law.

Answer 41

inductance Faraday

Question 42

Arterial tranducers are barometer or manometer?

Answer 42

manometer, need to zero to atmospheric pressure

Question 43

Capacitance =

Answer 43

A / d * increase surface area * decrease distance to increase capacitance

Question 44

Parallel capacitance Ct =

Answer 44

Ct = C1 + C2 + C3 like resistors in series

Question 45

What type of capacitance is this? What is Ct?

Answer 45

series capacitance