EEG BOARD MIDTERM EXAM STUDY
GUIDE QUESTIONS AND ANSWERS
100% VERIFIED. JUST RELEASED
1. A differential amplifier primarily functions based on which principle to reduce noise?
A. Active shielding of electrode wires
B. Increasing the gain of Input 1 only
C. High-pass filtering of low-frequency sway
D. Common Mode Rejection
Answer: D
Conceptual Explanation: Differential amplifiers eliminate signals that are common to
both inputs (noise) and amplify the difference between them, a process known as Common
Mode Rejection Ratio (CMRR).
2. What is the relationship between the Time Constant (TC) and the Low Frequency Filter
(LFF)?
A. A shorter TC corresponds to a lower LFF
B. A longer TC corresponds to a higher LFF
C. A shorter TC corresponds to a higher LFF
D. They are not mathematically related
,Answer: C
Conceptual Explanation: The Time Constant is inversely proportional to the frequency
(TC = 1 / (2 * pi * f)). Therefore, a shorter TC increases the LFF setting, attenuating more
low-frequency activity.
3. In the International 10-20 system, what percentage of the total distance between the
Nasion and Inion is the distance from Fpz to Fz?
A. 20%
B. 10%
C. 25%
D. 5%
Answer: A
Conceptual Explanation: The distance from Nasion to Fpz is 10%, and from Fpz to Fz is
20%. The total distance from Nasion to Fz is 30%.
4. If the sensitivity is 7 uV/mm and a wave measures 10 mm in height, what is the voltage of
the wave?
A. 70 uV
B. 0.7 uV
C. 1.4 uV
D. 700 uV
, Answer: A
Conceptual Explanation: Voltage is calculated by multiplying sensitivity by deflection (V =
S x D). 7 uV/mm * 10 mm = 70 uV.
5. Which filter would be most effective at reducing sweat sway artifact without significantly
distorting slow wave activity?
A. Increasing the LFF to 1.0 Hz
B. Decreasing the HFF to 15 Hz
C. Increasing the LFF to 5.0 Hz
D. Turning on the 60 Hz Notch filter
Answer: A
Conceptual Explanation: Sweat sway is a very low-frequency artifact (usually below 0.5
Hz). Increasing the LFF to 1.0 Hz can mitigate it, though 5.0 Hz might distort delta waves
too much.
6. A phase reversal between two channels in a bipolar montage generally indicates:
A. A referential electrode contamination
B. The location of the signal generator/focus
C. An equipment malfunction
D. The end of the electrode chain
Answer: B
GUIDE QUESTIONS AND ANSWERS
100% VERIFIED. JUST RELEASED
1. A differential amplifier primarily functions based on which principle to reduce noise?
A. Active shielding of electrode wires
B. Increasing the gain of Input 1 only
C. High-pass filtering of low-frequency sway
D. Common Mode Rejection
Answer: D
Conceptual Explanation: Differential amplifiers eliminate signals that are common to
both inputs (noise) and amplify the difference between them, a process known as Common
Mode Rejection Ratio (CMRR).
2. What is the relationship between the Time Constant (TC) and the Low Frequency Filter
(LFF)?
A. A shorter TC corresponds to a lower LFF
B. A longer TC corresponds to a higher LFF
C. A shorter TC corresponds to a higher LFF
D. They are not mathematically related
,Answer: C
Conceptual Explanation: The Time Constant is inversely proportional to the frequency
(TC = 1 / (2 * pi * f)). Therefore, a shorter TC increases the LFF setting, attenuating more
low-frequency activity.
3. In the International 10-20 system, what percentage of the total distance between the
Nasion and Inion is the distance from Fpz to Fz?
A. 20%
B. 10%
C. 25%
D. 5%
Answer: A
Conceptual Explanation: The distance from Nasion to Fpz is 10%, and from Fpz to Fz is
20%. The total distance from Nasion to Fz is 30%.
4. If the sensitivity is 7 uV/mm and a wave measures 10 mm in height, what is the voltage of
the wave?
A. 70 uV
B. 0.7 uV
C. 1.4 uV
D. 700 uV
, Answer: A
Conceptual Explanation: Voltage is calculated by multiplying sensitivity by deflection (V =
S x D). 7 uV/mm * 10 mm = 70 uV.
5. Which filter would be most effective at reducing sweat sway artifact without significantly
distorting slow wave activity?
A. Increasing the LFF to 1.0 Hz
B. Decreasing the HFF to 15 Hz
C. Increasing the LFF to 5.0 Hz
D. Turning on the 60 Hz Notch filter
Answer: A
Conceptual Explanation: Sweat sway is a very low-frequency artifact (usually below 0.5
Hz). Increasing the LFF to 1.0 Hz can mitigate it, though 5.0 Hz might distort delta waves
too much.
6. A phase reversal between two channels in a bipolar montage generally indicates:
A. A referential electrode contamination
B. The location of the signal generator/focus
C. An equipment malfunction
D. The end of the electrode chain
Answer: B
