Chapter 1. Basic EP

Question 1

The flow of electric current is measured in:

a. Ohms
b. Volts
c. Watts
d. Amperes

Answer 1

d. Amperes

Keywords: electriccurrent = amps

Question 2

What is the term used to denote the total oppostion to flow of alternating current in a circuity:

a. Reactance
b. Impedance
c. Inductance
d. Capacitance

Answer 2

b. Impedance or resistance (ohms)

Keywords: impedance / resistance to electric current flow

Question 3

What is the most common DC electric power source?

a. 60 cycle wall outlet
b. A charged capacitor
c. Transformer
d. Battery

Answer 3

d. Battery

Keywords: battery, DC Power

Question 4

Electric battery current has a frequency of:

a. 0 Hz
b. 60 Hz
c. 120 Hz
d. 1000 Hz

Answer 4

a. 0 Hz

Question 5

The elimination of vibrations at cetain frequencies is accmomplished through the use of electronic devices known as:

a. Diodes
b. Grids
c. Filters
d. Rectifiers

Answer 5

c. Filters

Keywords: filters

Question 6

When a DC defibrillator “charges” it stores electrical energy in its:

a. Batteries
b. Capacitors
c. Transformers
d. Photovoltaic cells

Answer 6

b. Capacitors

Question 7

7. EP lab external defibrillators should be tested by:

a. Discharging paddles into a dummy load
b. Discharging paddles against each other
c. Measuring paddle & cable resistance
d. Evaluating a defibrillaiton threshold

Answer 7

a. Discharging paddles into a dummy load

Keywords: Test defib. on a dummy load

Question 8

8. The Watt Second (or Joule) is a unit of:

a. Current
b. Energy
c. Resistance
d. Rate of power usage

Answer 8

b. Energy

Keywords: Energy = Watt Seconds

Question 9

What os the current drawn by a resistor of 100 ohms, if a 10 volt battery is applied across it?

a. 0.1 amp
b. 10 amp
c. 100 amp
d. 1000 amp

Answer 9

a. 0.1 amp

I = V/R = 10v/100Ω = 0.1 amp or 100 milliamps.

Keywords: Ohms law, electric current

Question 10

Using Ohm’s calculate the amount of current drawn by a pacemaker if it’s load resistance is 200 )hm;s and the pacing voltage is 1 volt (Use Ohm’s law):

a. 0.5 mA
b. 2 mA
c. 5 mA
d. 20 mA

Answer 10

c. 5 mA

Simple Ohm’s law: I = V/R = 1000 Mv/200 ohm = 5 mA.

Question 11

In electrical injury, the pathway of current most likely to be fatal is:

a. Hand-to-hand
b. Hand-to-foot
c. Foot-to-foot
d. Foot-to-ground

Answer 11

A. Hand-to-hand

Keywords: Worse electrical shock path = hand-to-hand

Question 12

For maximum electrical safety, the ECG monitored patient should be _____, and the monitor chassis should be _____ or nonconductive.

a. Grounded, Grounded
b. Grounded, Ungrounded
c. Ungrounded, Ungrounded
d. Ungrounded, Grounded

Answer 12

d. Ungrounded, Grounded

Question 13

In the ICU when recording an intracardiac ECG from a pacing electrode or pericardiocentesis needle in the heart, it is safest to:

a. Ground the ECG monitor to a water pipe
b. Ground the patient to a water pipe
c. Use a battery powered monitor
d. Use low resistance R2 defibrillation pads as the limb electrodes

Answer 13

c. Use a battery powered monitor

Keywords: intracardiac ECG, use battery powered monitor

Question 14

When you plug in an electric instrument, you are alaramed when sparks fly from the wall outlet as shown. THe most likely electrical safery problem is a:

a. Outlet miswired
b. Broken insulation on the power cord
c. Machine off-on switch was left turned-on
d. Machine fuse shorted out

Answer 14

c. Machine off-on switch was never turned-off

Keywords: sparks, machine left turned-on

Question 15

The prefix “centi” corresponds to”

a. 1/10
b. 1/100
c. 1/1000
d. 1/1,000,000

Answer 15

b. 1/100 = “centi”

Keywords: prefix centi-