Question 1

Amplitude of the electromagnetic sine wave is defined as:
A) The length of the electronic vector at one-half peak width.
B) The width of the electronic vector at maximum peak height.
C) The length of the electronic vector at maximum peak height.
D) The area under the sine wave.

Accepted Answer

The amplitude of an electromagnetic sine wave is defined as the length of the electronic vector at maximum peak height, which represents the maximum extent of the wave from its equilibrium position.

Question 2

What is the concentration of serum uric acid in a solution whose absorbance is 0.098, cuvet pathlength, 1.0 centimeters, absorptivity is 0.102 L g^-1cm^-1? A) 0.96 mg/L B) 0.009 g/L C) 0.48 g/L D) 1.96 g/L

Accepted Answer

Using Beer-Lambert Law, concentration = absorbance / (pathlength * absorptivity) = 0.098 / (1.0 * 0.102) = 0.96 mg/L.

Question 3

What is the concentration of creatinine in a serum sample if given the following? A_test = 0.150 A_standard = 0.90 C_standard = 1.0 mg/dL A) 0.25 mg/dL B) 0.5 mg/dL C) 0.7 mg/dL D) 0.167 mg/dL

Accepted Answer

The concentration of creatinine in the serum sample is calculated using the ratio of the absorbance of the test sample to the absorbance of the standard, multiplied by the concentration of the standard. Thus, $0.150 / 0.90 \times 1.0 \, \text{mg/dL} = 0.167 \, \text{mg/dL}$.

Question 4

Which of the following types of light sources emits radiation that changes in intensity very slowly as a function of wavelength?
A) Pulsating source
B) Line source
C) Continuum source
D) Microwave source

Accepted Answer

A continuum source emits radiation that changes in intensity very slowly as a function of wavelength, providing a continuous spectrum rather than discrete lines or rapid changes. Examples include incandescent bulbs and the sun.

Question 5

Filters and diffraction gratings are examples of which of the following?
A) Monochromators
B) Cuvettes
C) Light sources
D) Slits

Accepted Answer

Monochromators are devices used to isolate specific wavelengths of light from a broader spectrum. Filters and diffraction gratings are common components in monochromators for this purpose. Filters selectively transmit light of certain wavelengths, while diffraction gratings disperse light into its component wavelengths, allowing for the selection of a specific wavelength.

Question 6

The wavelength in nanometers at peak transmittance is termed:
A) Spectral bandwidth.
B) Stray light.
C) Nominal wavelength.
D) Electromagnetic spectrum.

Accepted Answer

The nominal wavelength refers to the specific wavelength in nanometers at which a device or material exhibits peak transmittance or performance.

Question 7

Bandpass is defined as:
A) The range of wavelengths at a point halfway between the baseline and the peak.
B) The half power point or full width at half maximum.
C) The total range of wavelengths transmitted.
D) The product of parallel beams of radiation.

Accepted Answer

Bandpass refers to the total range of wavelengths (or frequencies) that a system or device can transmit or pass through, which is why option C is correct.

Question 8

A photomultiplier tube functions to:
A) Reduce the electronic signal produced as photons cascade from dynode to dynode.
B) Increase the electronic signal produced as photons cascade from dynode to dynode.
C) Decrease the number of transmitted photons from the cuvette.
D) Reduce in a logarithmic fashion the electronic signal created at the cathode.

Accepted Answer

A photomultiplier tube amplifies the electronic signal produced as photons hit the photocathode, releasing electrons that are then accelerated and multiplied through a series of dynodes, resulting in a significantly increased electronic signal.

Question 9

Didymium and holmium oxide filters are used to assess:
A) Wavelength accuracy.
B) Voltage values.
C) Stray light.
D) Photometric accuracy.

Accepted Answer

Didymium and holmium oxide filters are used to assess wavelength accuracy in spectrophotometers because they have well-defined absorption peaks at known wavelengths.

Question 10

Which of the following is a cause of stray light failure in a spectrophotomer?
A) Fingerprints on a cuvette
B) Misaligned monochromator
C) Room light entering the spectrophotometer and impinging upon the detector
D) A dirty holmium oxide filter

Accepted Answer

Room light entering the spectrophotometer and impinging upon the detector can cause stray light failure in a spectrophotometer.

Question 11

Light reflecting off a urine dipstick absorbent surface is an example of which of the following?
A) Specular reflectance
B) Diffuse reflectance
C) Refractance
D) Chemiluminescence

Accepted Answer

Diffuse reflectance occurs when light is scattered in many directions after hitting a rough or uneven surface, such as the absorbent material of a urine dipstick, making B the correct choice. Specular reflectance would involve a smooth surface reflecting light in a single direction, refractance involves the bending of light as it passes through different mediums, and chemiluminescence is a chemical reaction producing light, none of which accurately describe the scenario with the urine dipstick.

Question 12

Which of the following describes atomic absorption spectroscopy?
A) The transmittance of monochromatic electromagnetic radiation by an element in its excited state
B) The measurement of the electromagnetic radiation emitted by an element
C) The release of electromagnetic radiation due to a chemical reaction
D) The absorption of monochromatic electromagnetic radiation by an element in its ground state with a net zero charge

Accepted Answer

Atomic absorption spectroscopy involves the absorption of monochromatic electromagnetic radiation by atoms in their ground state, which is used to measure the concentration of specific elements in a sample.

Question 13

Which of the following statements best illustrates the difference between photons from fluorescent emission and the excitation photons?
A) Emission photons are higher energy and longer wavelength.
B) Emission photons are lower energy and longer wavelength.
C) Emission photons are lower energy and shorter wavelength.
D) Emission photons are negatively charged and have zero mass.

Accepted Answer

Emission photons are lower in energy and have a longer wavelength compared to the excitation photons. This is because some energy is lost in non-radiative processes before the fluorescent emission occurs.

Question 14

The polarization of light in fluorescent polarization immunoassay allows the measurement of which of the following?
A) Bound fraction in the presence of the free fraction
B) Only the bound fraction after the free fraction is removed
C) Both bound and free fractions
D) Antibodies to fluorescent label

Accepted Answer

Fluorescent polarization immunoassay measures the bound fraction in the presence of the free fraction by detecting the polarization of light emitted by fluorescent labels, which changes based on the molecular rotation of the bound versus free labeled molecules.

Question 15

A chelate of europium (Eu³⁺) is used in which of the following assays? A) Radioimmunoassays B) Chemiluminescent immunoassays C) Time-resolved fluorescent immunoassays D) Fluorescent polarization immunoassays

Accepted Answer

Chelates of europium are used in time-resolved fluorescent immunoassays due to their long-lived fluorescence, which allows for the separation of the fluorescence signal from background noise, improving assay sensitivity and specificity.

Question 16

Oxidation of acridinium esters by hydrogen peroxide in the presence of peroxidase produces which of the following?
A) Fluorescence
B) Phosphorescence
C) Translucence
D) Chemiluminescence

Accepted Answer

Oxidation of acridinium esters by hydrogen peroxide in the presence of peroxidase produces chemiluminescence. This reaction emits light as a product of the chemical reaction, which is a characteristic of chemiluminescence.

Question 17

Turbidimetry is the measurement of the reduction in light transmission caused by:
A) Particle formation.
B) Chelation of metals.
C) Slowing of the spin rotation of electrons.
D) Increase in excitation photon energy.

Accepted Answer

Turbidimetry measures the reduction in light transmission through a sample, which can be caused by the formation of particles in the sample that scatter the light.

Question 18

The presence of particulates in a urine sample measured by a refractometer will result in which of the following?
A) An increase in reflectance of the solution
B) A change in the critical angle of the light as it passes through the solution
C) An increase in energy of the solute particles that results in a release of light energy
D) A change in Rayleigh scatter patterns

Accepted Answer

The presence of particulates in a urine sample affects the refractive index, altering the critical angle of light passing through the solution, which is measured by a refractometer.

Question 19

Which of the following accounts for the temperature rise in freezing point osmometry?
A) Heat of separation
B) Thermal currents flowing through the ethylene glycol
C) Heat of fusion
D) Heat of conduction

Accepted Answer

The temperature rise in freezing point osmometry is accounted for by the heat of fusion. This is the heat released when a liquid becomes a solid, which in the context of osmometry, affects the temperature measurement as the sample freezes.

Question 20

Which of the following electrical devices senses the freezing point of a solution in an osmometer?
A) A pH electrode
B) A pressure transducer
C) A conductivity electrode
D) A thermistor

Accepted Answer

A thermistor is used in an osmometer to sense the freezing point of a solution because it is a type of resistor whose resistance varies significantly with temperature, allowing it to detect the change in temperature that occurs at the freezing point.

Quiz 4: Instrumentation, Laboratory Automation, and Informatics

Amplitude of the electromagnetic sine wave is defined as:

What is the concentration of serum uric acid in a solution whose absorbance is 0.098, cuvet pathlength, 1.0 centimeters, absorptivity is 0.102 L g-1cm-1?

What is the concentration of creatinine in a serum sample if given the following? Atest = 0.150 Astandard = 0.90 Cstandard = 1.0 mg/dL

Which of the following types of light sources emits radiation that changes in intensity very slowly as a function of wavelength?

Filters and diffraction gratings are examples of which of the following?

The wavelength in nanometers at peak transmittance is termed:

Bandpass is defined as:

A photomultiplier tube functions to:

Didymium and holmium oxide filters are used to assess:

Which of the following is a cause of stray light failure in a spectrophotomer?

Light reflecting off a urine dipstick absorbent surface is an example of which of the following?

Which of the following describes atomic absorption spectroscopy?

Which of the following statements best illustrates the difference between photons from fluorescent emission and the excitation photons?

The polarization of light in fluorescent polarization immunoassay allows the measurement of which of the following?

A chelate of europium (Eu3+) is used in which of the following assays?

Oxidation of acridinium esters by hydrogen peroxide in the presence of peroxidase produces which of the following?

Turbidimetry is the measurement of the reduction in light transmission caused by:

The presence of particulates in a urine sample measured by a refractometer will result in which of the following?

Which of the following accounts for the temperature rise in freezing point osmometry?

Which of the following electrical devices senses the freezing point of a solution in an osmometer?

What is the concentration of serum uric acid in a solution whose absorbance is 0.098, cuvet pathlength, 1.0 centimeters, absorptivity is 0.102 L g^-1cm^-1?

What is the concentration of creatinine in a serum sample if given the following? A_test = 0.150 A_standard = 0.90 C_standard = 1.0 mg/dL

A chelate of europium (Eu³⁺) is used in which of the following assays?