Physics Concepts: Radioactivity and Sound

Radioactive Counting Error

• If radioactive counting is measured for four times longer with constant activity, the absolute error doubles.

SI Units

• Speed and weight are not SI units.

Stochastic Biological Effect

• The frequency of the effect increases with the dose.
• This effect is heritable.

Light Ray Change in the Eye

• The direction of a light ray changes most significantly as it enters the cornea.

Volume Velocity of Viscous Liquid

• The volume velocity is directly proportional to the pressure difference.

Sound Source and Detector Frequency

• If the sound source approaches the detector, the detected frequency is higher than the emitted frequency.
• Stokes' law states the diffusion constant is inversely proportional to the viscosity of the medium.

Blood Dilution Isotopes

• ⁵¹Cr and ¹³¹I are used to measure the dilution volume of blood.

True Statements

• The transmission speed of higher pitched sounds is slower than that of deeper sounds.
• Mediated diffusion is faster than simple diffusion.

Radioactive Isotope Decay Constant

• The decay constant is approximately 0.7/s for a half-life of 1 second.

Resting Brain EEG Waves

• The resting brain emits alpha waves.

Diverging Lens

• A biconcave lens is a diverging lens.
• The refractive index of the lens must be greater than the refractive index of the medium.

Brain Imaging and Absorption

• CT scans are affected by skull absorption, reducing the resolution of brain images.

Laplace Law

• The tension in the wall of a circular pipe is created by the pressure inside.

Blood Pressure Change (Sudden Standing)

• Blood pressure decreases in the brain when a person stands up suddenly.

Laminar Blood Volume Velocity

• The volume velocity of laminar blood doubles if the radius of the blood vessel increases by 19%.

Imaging Procedure and Ionizing Radiation

• CT and PET scans use ionizing radiation to create images.

Dark-Adapted Eye Sensitivity

• The dark-adapted eye is more sensitive.

Coherent Light Wave Interference

• Two light waves cause permanent interference if they are coherent and their phase difference is constant.

SI Unit for 1/s

• The SI unit for 1/s is frequency and the decay constant.

Korotkoff Noise

• Korotkoff noise occurs when the air bag pressure falls below the peak pressure created during the heartbeat.

Ionizing Radiation and Biological Effect

• 3 MeV alpha radiation has the greatest biological effect when energy is held constant.

Ultracentrifugation and Movement

• A lower frictional coefficient leads to faster movement, and a smaller diffusion constant to slower movement in ultracentrifugation.

Positron Beta Decay

• The atomic number increases by one, and the mass number does not change.

Effective Half-Life of Radioisotope

• The effective half-life of a radioactive isotope introduced into the body is less than its biological half-life.
• It is equal to the reciprocal of the sum of the reciprocals of the two half-lives.

Not True about Alpha Particles

• Alpha particles are not protons or high-energy photons.

EEG Wave Amplitude

• Delta waves have amplitudes in the range of 50-100 μV.

Isotope Decay Percentage

• After 20 minutes, 75% of a 10-minute half-life isotope decays.
• After 40 minutes, 6.25% of a 10-minute half-life isotope remains undecayed.

Refractive Index of Lenses

• The refractive index of a lens system is the sum of the refractive indices of the individual lenses in contact.

Radioactive Source Activity

• The activity of a radioactive source is the number of radioactive decays per second.

Stokes' Law and Resistance Force

• Stokes' Law describes the resistance force on a sphere moving in a viscous liquid.

Electromagnetic Imaging Procedures

• Echoencephalography does not use electromagnetic radiation to create images.

Refraction and Medium Properties

• Refraction at the boundary of two media depends on the density of the media.
• The relative refractive index is also influential.

Light Wave Interactions

• Two light waves that meet can add their evecations together.

Object Outside Focal Length of Converging Lens

• When an object is outside the focal length of a converging lens, the image is real and inverted.

Frequency for Field Diathermy

• The frequency used for field diathermy is 0.03 GHz.

Ultrasound Frequency Band

• The ultrasound frequency band used in medical applications is 2-18 MHz.

Pressure in a Pipe

• The pressure increases if the diameter of a pipe increases; and decreases when the diameter decreases.

Diffusion Constant Dependence

• The diffusion constant depends on the shape of the diffusing particle and temperature.

MRI for Cancerous Tumors

• MRI is the most accurate imaging method for detecting cancerous tumors.

Braking Radiation

• Braking radiation performance depends on the accelerating voltage.

Patch-Clamp Technique

• The patch-clamp technique greatly narrows the membrane area to be tested.

EEG Wave Frequency

• Teta waves have frequencies between 4 Hz and 7 Hz.

Solutions That Cause Hemolysis

• A hypotonic solution causes hemolysis or rupture of red blood cells.

ECG Peak Magnitude

• The magnitude of the ECG QRS complex peak is 1–2 mV.

Lambert's Law

• The decrease in light intensity passing through a material depends on the thickness of the material.
• The amount of light passing through a material is proportional to the thickness of the material.

Blood Pressure and Sudden Standing

• The blood pressure in a standing person is highest in the heart.

Volume Velocity and Viscosity

• The volume velocity of a viscous liquid is inversely proportional to viscosity.

Isotopic NaCl Solution Concentration

• The concentration of Na in an isotonic NaCl solution is 0.9%.

Effective Dose

• Effective dose is measured in J/kg.

Decreasing Measurements

• The error in measurements decreases when there is an increase in the number of measurements.

Non-Basic SI Quantity

• Weight and the speed of light in a vacuum are not basic SI quantities; they are derived quantities.

False Statement about Dark Adaption

• It is not true that dark adaptation takes minutes.

Mechanical Energy of a Cat

• A cat's mechanical energy is greater when sitting still atop a wall than when moving across the floor.

Sound Statement and Truth

• Sound of higher pitches has lower transmission compared to deeper sounds.
• Thermography has no negative impact on the fetus's health.

Isotopic Decay Percentage

• After 1 hour, 12.5% of 20-minute half-life isotope is not decayed.

Diffusion Constant Dependence

• The diffusion constant is not dependent on pH value or the density of the medium.

Alpha Particle Statements

• Alpha particles are doubly ionized helium atoms and are helium nuclei.

Sound and Penetration Statements

• Mediated diffusion is a faster diffusion process compared to simple diffusion.
• Sounds of higher pitches have lower transmission capacity as compared to deeper sounds.

Refraction and Medium Density

• The refraction at a medium boundary depends on the density of the respective media.

Electron Wavelength in Vacuum

• The wavelength of an electron in a vacuum is 0.3 µm.

Visual Acuity and Eye Adaptation

• The light-adapted eye has poor visual acuity and the dark-adapted eye is more sensitive.

Different Question Types

• A summary of statements is required.

Bremsstrahlung

• Bremsstrahlung's power depends on the accelerating voltage.
• The impulse's dimensions are kg⋅m/s.
• The light atomic nucleus is approximately 10^-15 meters in size.

Performance Definition

• Performance is defined as energy per unit time.

Half Radian Value

• A half radian is approximately 28.672 degrees.

Beta Radiation Spectrum

• Beta radiation has a continuous spectrum and maximum energy values.
• It is not necessarily constant, meaning that the particles do not all have the same energy.

Mesophases Properties

• Mesophases demonstrate anisotropy, which is a property that varies depending on direction, or axis.

Sine Function Application

• The sine function's application with the argument remains consistent with the same arguments, or time, after an integer multiple of 2π is added to the original argument.
• For any angles separated by a multiple of 2π, the output of a sine function remains the same.

Half-Life and Decay

• Remaining after three half-lives, a quantity of material will be 12.5% of the original.

Lambert-Bert Law Application

• Lambert-Bert's law applies in relation to light reflection from thin solutions.

Torque Types

• Bending and twist are examples of torque types.

Thermodynamically Isolated Systems

• Systems that do not interact with external factors or have a constant energy are thermodynamically isolated systems.

Equilibrium in Mechanical Systems

• All the forces and torque add up to zero, which then leads to equilibrium in a mechanical system.

Isotherm Thermodynamics

• Isotherm thermodynamics exists when the temperature is constant.

Ionization and Electrons

• Ionization occurs when an electron is freed, becoming independent, or more specifically; free electrons, or electrons that are not associated with an atomic nucleus.

Bird Energy

• The bird's kinetic energy is about 50 J.

Sound Dimension

• The dimension corresponding to sound is ground frequency measurement.

X-ray Attenuation

• Elementary processes include photon effect, pair formation, and Compton scattering for x-ray attenuation.

Abbe Theory and Light Reflection

• Abbe theory is an idea which is applicable to light reflection upon thin substances.

Extensive Dimension

• Extensive dimensions include mass and volume.
• They are additive.

Ionized Radiations

• Beta radiation and Gamma radiation are types.

Lens Errors

• Errors in lenses include chromatic aberration and spherical aberration.

Beta Radiation Range

• Beta radiation's range in air is 10 cm to a few meters.
• In soft tissue, it spans a few millimeters.

Boltzmann's Distribution

• Boltzmann's distribution does not describe effective half-times or the bound state of electrons.

Heat Processes

• Types of heat processes include conduction and convection.