ECG Electrocardiogram Knowledge Answers and Questions 2

Question 1

Which lead is considered the ground (reference) electrode in a standard 12-lead ECG?

Accepted Answer

Right leg (RL)

Answer

Left leg (LL)

Answer

Right arm (RA)

Answer

V6

Question 2

At standard calibration, one small (1 mm) box on the horizontal axis represents how much time?

Accepted Answer

0.04 seconds

Answer

0.20 seconds

Answer

0.10 seconds

Answer

1.0 second

Question 3

The P wave on an ECG represents which electrical event?

Accepted Answer

Atrial depolarization

Answer

Ventricular depolarization

Answer

Ventricular repolarization

Answer

Atrial repolarization

Question 4

Where should the V1 chest electrode be placed?

Accepted Answer

4th intercostal space, right sternal border

Answer

4th intercostal space, left sternal border

Answer

5th intercostal space, midclavicular line

Answer

5th intercostal space, anterior axillary line

Question 5

A standard ECG is normally calibrated so that 10 mm of vertical deflection equals what voltage?

Accepted Answer

1 millivolt

Answer

0.5 millivolt

Answer

2 millivolts

Answer

10 millivolts

Question 6

Which artifact is most likely caused by patient muscle tremor or shivering?

Accepted Answer

Somatic (muscle) tremor artifact

Answer

Wandering baseline

Answer

60-cycle interference

Answer

Flat line

Question 7

The normal duration of a QRS complex in an adult is approximately:

Accepted Answer

0.06 to 0.10 seconds

Answer

0.12 to 0.20 seconds

Answer

0.20 to 0.40 seconds

Answer

0.40 to 0.60 seconds