Biophysics Questions Quiz

Biophysics Questions and Answers

• Absolute Error Reduction: Measuring radioactive counting for four times longer at constant activity reduces the absolute error to a quarter.

• Non-SI Base Unit: Weight is not an SI base unit; speed, luminous intensity, and temperature are.

• Stochastic Biological Effect: Inheritable, its frequency increases with dose; the dose does not need to exceed a threshold for its occurrence.

• Light Beam Direction Change: The most significant change in light beam direction occurs at the boundary between the eye's lens and vitreous body.

• Volumetric Velocity and Pressure Difference: Volumetric velocity of a viscous liquid is directly proportional to the pressure difference.

• Osmosis Pressure and Sound Frequency: Osmosis pressure is equal to the partial pressure of the solvent; if a sound source approaches a detector, the detected frequency increases.

• Ideal Fluid Types: Non-Newtonian fluids are not an ideal fluid type.

• Blood Dilution Isotopes: ⁵¹Cr is used to measure blood dilution volume.

• Light Refraction and Medium Refractive Index: When a light beam enters a medium with a higher refractive index into a medium with a lower refractive index, the angle of refraction is less than the angle of incidence.

• Radioactive Isotope Decay Constant: The decay constant of a radioactive isotope with a 1-second half-life is approximately 0.7/s.

• EEG Waves in Resting Brain: A resting brain emits alpha waves.

• Biconcave Lens Properties: A biconcave lens is a spray lens when the refractive index of the medium is less than the refractive index of the lens.

• Imaging Equipment Affecting Brain Image Resolution: CT imaging significantly worsens the resolution of brain images due to absorption by skull bone.

Laplace Law

• Laplace Law: Describes the tension created by pressure in the wall of a circular pipe.

Blood Pressure Changes

• Blood Pressure Changes (Sudden Standing): Blood pressure decreases in the brain of a person who suddenly stands up.

Blood Flow Rate Changes

• Blood Flow Rate and Vessel Radius: If the radius of a vessel increases by 19%, the volumetric rate of blood flow increases by approximately twofold.

Imaging Methods and Ionizing Radiation

• Imaging Methods Using Ionizing Radiation: CT and PET imaging use ionizing radiation to create images.

Visual Acuity and Eye Adaptation

• Dark-Adapted Eye: Dark-adapted eyes are the most sensitive; visual acuity is poor in the dark-adapted state.

• Eye Adaptation: The light-adapted state develops within minutes when transitioning from dark to light.

• Eye Structure: The retina contains approximately 20 times as many rods as cones.

Light Wave Interference

• Persistent Interference: Two light waves meet, causing persistent interference if their wavelengths are equal and they are coherent (constant phase difference).

SI Units

• SI Unit (1/s): The SI unit of frequency is 1/s, as is the decay constant.

Korotkov Sounds

• Korotkov Noise: A consequence of blood flow becoming laminar in an artery, Korotkov sounds disappear when pressure reaches diastolic.

Lens Image Formation

• Lens Image Types (Real vs. Virtual): A straight object within focal length produces a virtual and upright image.

Ionizing Radiation Biological Effect

• Ionizing Radiation Biological Effect: Alpha radiation has the greatest biological effect for the same energy transferred, compared to other ionizing radiations such as X-rays, neutrons or protons.

Ultracentrifuging

• Ultracentrifuging: Heavier particles settle faster; lower diffusion constant means slower movement.

Beta Decay

• Beta Decay, Positron: Mass number decreases by 1 in beta decay with a positron emission.

Radioactive Isotope Half-life

• Effective Half-life: The effective half-life of a radioactive isotope administered to the body is less than the biological half-life.

Alpha Particles and Properties

• Alpha Particles: Alpha particles are helium nuclei (doubly ionized helium).

EEG Waves and Amplitude

• EEG Wave Amplitude: The amplitude range of Beta waves is between 50 and 100 µV.

Radioactive Isotope Decay

• Radioactive Isotope Decay (13N): After 20 minutes, 75% of the 10-minute half-life isotope ¹³N has decayed.

Lens Refractive Power

• Lens Refractive Power: The refractive power of lens systems is the sum of the refractive powers of the individual lenses in contact.

Radioactive Source Activity

• Radioactive Source Activity: The activity of a radioactive source is measured as the number of radioactive decays per second.

Imaging Method and Electromagnetic Radiation

• Imaging Method Without Electromagnetic Radiation: Echoencephalography does not use electromagnetic radiation.

Diffusion Constant

• Diffusion Constant and Properties: The diffusion constant depends on temperature, medium viscosity, and the shape of the diffusing particle.

Refraction at Media Boundary

• Refraction and Media Properties: The degree of refraction is determined by the relative refractive index of the second medium to the first.

Light Wave Interaction

• Light Wave Interaction: Meeting light waves can result in interference, with their intensities adding up.

Lens Image Formation (Real vs. Virtual, Object Position)

• Lens Image Types (Real vs. Virtual): A real and upright object outside the focal length of a convex lens produces a real and inverted image.

Diathermy Frequencies

• Diathermy Frequencies: Ultrasound frequencies used in medical applications range from 2-18 MHz.

Liquid Flow Pressure Change

• Ideal Fluid Flow Pressure: Pressure in an ideal fluid flowing in a pipe decreases when the pipe diameter increases.

Ideal Liquid Flow Pressure Change

• Ideal Liquid Flow Pressure (Decreasing Diameter): Pressure in an ideal liquid flowing in a pipe increases when the pipe diameter decreases.

Diffusion Constant Dependence

• Diffusion Constant Dependence: The diffusion constant depends on the temperature, density of the medium, and the shape of the diffusing particle.

Imaging Equipment and Cancer Detection

• Imaging Equipment for Tumor Detection: MRI offers the most accurate technique for pinpointing cancerous tumors among the options provided.

Braking Radiation

• Braking Radiation: Minimum wavelength of braking radiation depends on the anode material; its power and total energy depend on the accelerating voltage; the spectrum includes distinct peaks.

Patch-Clamp Technique

• Patch-Clamp Technique: It maintains the membrane's voltage or tension.

EEG Wave Frequency

• EEG Wave Frequency: Delta waves have frequencies from 4 to 7 Hz.

Infusion Solutions and Hemolysis

• Hemolysis-Causing Infusion: Hypotonic infusion solutions cause hemolysis.

ECG Signal

• ECG QRS Complex Amplitude: The normal QRS complex amplitude in a two-lead ECG signal is 1-2 mV.

Lambert's Law

• Lambert's Law: States that the intensity of light decreases through a material, varying with its thickness.

Blood Pressure Location

• Blood Pressure Location: Blood pressure is highest in the heart when a person is standing.

Liquid Volumetric Rate and Viscosity

• Liquid Volumetric Rate and Viscosity: The volumetric rate of a viscous liquid is inversely proportional to viscosity.

Isotonic NaCl Saline Concentration

• Isotonic NaCl Concentration: The concentration of Na in isotonic NaCl saline is 0.9%.

Effective Dose Unit

• Effective Dose Unit: The unit of effective dose is J/kg.

Measurement Error

• Measurement Error: Empirical standard deviation decreases with increased measurements, the error of the mean decreases.

Non-SI Quantities

• Non-SI Quantities: speed of light in vacuum, luminous intensity, and weight are not SI base quantities, neither is Fermi.

Dark-Adapted Eye

• Dark-Adapted Eye: The dark-adapted eye is the most sensitive, with poor visual acuity, and the dark-adapted state develops within minutes when transitioning to darkness.

Mechanical Energy

• Mechanical Energy (Kitten): Mechanical energy is the same in both cases (sitting/running).

Diffusion and Movement Direction

• Diffusion Direction: Mediated diffusion moves particles from a lower concentration area to a higher concentration one across a membrane, opposite to simple diffusion.

Radioactive Isotope Decay (11C)

• Radioactive Isotope Decay (11C): After 1 hour, 12.5% of the ¹¹C isotope with 20-minute half-life hasn't decayed.

• Diffusion and Properties: Globular proteins have lower diffusion constants compared to fibrillar proteins. Diffusion constant is proportional to temperature, but inversely proportional to viscosity.

Units of Measurements

• SI Units (Radioactivity): The unit for radioactive activity is Becquerel (Bq).

Radioactive Isotope Decay (13N)

• Radioactive Decay (13N): After 40 minutes, 6.25% of the isotope ¹³N (10-minute half-life) hasn't decayed.

Electronic Wavelength

• Electron Wavelength: Wavelength of an accelerated electron in a vacuum (1.5 V potential) is approximately 90 nm.

Light Wave Interference Conditions

• Light Wave Interference Conditions: Persistent interference occurs between coherent light waves.

SI Unit (Time)

• SI Unit (Time): The second is the SI unit for time/period time.

¹³¹I Activity

• ¹³¹I Activity: A normal activity for ¹³¹I is 2 mCi for thyroid tests.

Beta Particles

• Beta Particles: Beta particles are high-energy electrons.

Voltage-Clamp Technique

• Voltage-Clamp Technique: The technique holds membrane voltage at a preset level.

EEG Wave Amplitudes

• EEG Wave Amplitudes: Delta waves have maximum amplitudes less than 20 µV.

Absolute Error Calculation

• Absolute Error Calculation: The absolute error (difference) calculation in multiple measurements involves calculating the square root of the sum of the squares of absolute errors for each quantity.

Radioactive Decay Constant

• Radioactive Decay Constant and Half-life: The decay constant is inversely proportional to the half-life.

Microwave Frequency

• Microwave Frequency: 2.54 GHz is used for microwave sliding terminals.

Infusion Solution Effect

• Infusion Solution Effect: Hypertonic infusion solutions cause plasmolysis (shrinkage of cells).

Irradiation Dose Unit

• Irradiation Dose Unit: The SI unit for irradiation dose is gray (Gy).

Capacitor Field Diathermy Frequency

• Capacitor Field Diathermy Frequency: 2770 kHz and 0.03 GHz to 100 kHz ranges are used for capacitor field diathermy

Real Object Image Formation (Lens)

• Real Image Formation (Lens): A real, inverted image is formed when a real object is placed beyond the focal length of a converging lens.

Diffusion Constant Dependence (Variables)

• Diffusion Constant Variables: The diffusion constant does not depend on the pH value of the medium.

Alpha Particles Properties

• Alpha Particle Properties: Alpha particles are helium nuclei (doubly ionized helium atoms).