About this Study Set
This study set covers Electromagnetism through
20 practice questions.
A collection of advanced questions regarding the electromagnetic properties of biological systems and medical diagnostics. Every question includes the correct answer so you can learn as you go — pick any format above to get started.
Questions & Answers
Browse all 20 questions from the
Electromagnetism in Human Physiology study set below.
Each question shows the correct answer — select a study format above to practice interactively.
1
What is the primary ionic mechanism responsible for the resting membrane potential of a neuron, typically measured at approximately -70 mV?
-
A
Sodium-potassium pump activity
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B
Calcium ion influx
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C
Chloride ion sequestration
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D
Potassium ion efflux through leak channels
2
In Magnetoencephalography (MEG), which physical principle is utilized to detect the extremely weak magnetic fields produced by electrical activity in the brain?
-
A
Superconducting Quantum Interference Devices (SQUIDs)
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B
Hall effect sensors
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C
Faraday cage resonance
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D
Piezoelectric transducers
3
During a standard Electrocardiogram (ECG), the P-wave corresponds to which specific electromagnetic event in the heart?
-
A
Ventricular repolarization
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B
Atrial depolarization
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C
Ventricular depolarization
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D
Atrioventricular node conduction delay
4
What is the specific physical property of deoxyhemoglobin that allows it to be distinguished from oxyhemoglobin in functional Magnetic Resonance Imaging (fMRI)?
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A
Diamagnetism
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B
Paramagnetism
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C
Ferromagnetism
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D
Superconductivity
5
The Hodgkin-Huxley model describes the mathematical relationship between the membrane potential and which specific biophysical property?
-
A
Thermal conductivity
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B
Ion channel conductance
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C
Fluid viscosity
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D
Molecular binding affinity
6
Which ion is primarily responsible for the 'plateau phase' of a cardiac action potential, preventing tetanic contraction?
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A
Potassium
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B
Magnesium
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C
Calcium
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D
Phosphate
7
What is the range of the magnetic field strength typically generated by the human heart, detectable by high-sensitivity sensors?
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A
1-5 microtesla
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B
10-50 picotesla
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C
100-500 millitesla
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D
1-5 nanotesla
8
In Electromyography (EMG), the motor unit action potential (MUAP) represents the summation of electrical activity from which structures?
-
A
All muscle fibers innervated by a single motor neuron
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B
The entire muscle belly
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C
The neuromuscular junction only
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D
The sensory afferent nerve fibers
9
Which type of radiation is utilized in Positron Emission Tomography (PET) to detect metabolic activity, relying on the annihilation of positrons and electrons?
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A
Alpha particles
-
B
511 keV gamma photons
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C
Beta-minus radiation
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D
X-rays
10
What role does the myelin sheath play in the electromagnetic propagation of a nerve impulse?
-
A
Increases membrane resistance and decreases capacitance
-
B
Decreases membrane resistance and increases capacitance
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C
Acts as a ferromagnetic insulator
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D
Converts electrical energy to chemical energy
11
In the context of the Nernst equation, what does the variable 'z' represent in the calculation of the equilibrium potential for a specific ion?
-
A
Ion concentration
-
B
Temperature in Kelvin
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C
The valence of the ion
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D
The gas constant
12
The 'QRS complex' in an ECG is electromagnetically generated by which cardiac process?
-
A
Atrial repolarization
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B
Ventricular depolarization
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C
Sinoatrial node firing
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D
Ventricular repolarization
13
What physical phenomenon makes the human body partially transparent to high-frequency radio waves in MRI?
-
A
The spin of hydrogen nuclei in water
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B
The ionization of oxygen
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C
The diamagnetic properties of carbon
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D
The high electrical resistance of bone
14
In bioelectricity, what is the 'space constant' (lambda) defined as in cable theory regarding nerve fibers?
-
A
The distance at which a graded potential decays to 37% of its original value
-
B
The velocity of the action potential
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C
The thickness of the axon membrane
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D
The frequency of the ion channel oscillation
15
Which structure in the inner ear transduces mechanical vibrations into electromagnetic signals via hair cell depolarization?
-
A
Organ of Corti
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B
Semicircular canals
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C
Stapes
-
D
Eustachian tube
16
Transcranial Magnetic Stimulation (TMS) induces electrical currents in the brain by utilizing which physical principle?
-
A
Coulomb's Law
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B
Electromagnetic induction (Faraday's Law)
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C
The Doppler effect
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D
The Bernoulli principle
17
At the chemical synapse, the conversion of an electrical signal to a chemical signal and back to an electrical signal occurs primarily through which mechanism?
-
A
Direct electron tunneling
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B
Ligand-gated ion channels
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C
Quantum tunneling
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D
Active transport of protons
18
What is the primary electromagnetic effect observed during the repolarization phase of an action potential?
-
A
Sodium influx
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B
Potassium efflux
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C
Calcium sequestration
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D
Magnesium uptake
19
Which medical imaging modality uses the gyromagnetic ratio of the hydrogen nucleus?
-
A
CT scanning
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B
PET scanning
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C
Magnetic Resonance Imaging
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D
Ultrasound
20
In the human eye, the 'ERG' (Electroretinogram) measures the electrical response of which layer to light stimulation?
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A
The lens
-
B
The cornea
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C
The retina
-
D
The iris
