250+ TOP MCQs on Transmission of Video Images and Answers

Biomedical Instrumentation Multiple Choice Questions on “Transmission of Video Images”.

1. Blood cell counters, operating on the principle of conductivity change, which occurs each time a cell passes through an orifice, are generally known as ________________
a) optical method
b) electrical conductivity
c) coulter Counter
d) microscopic method
Answer: c
Clarification: Blood cell counters, operating on the principle of conductivity change, which occurs each time a cell passes through an orifice, are generally known as Coulter Counters. The method was patented by Coulter in 1956 and it forms the basis of several particle counting instruments manufactured by a number of firms throughout the world.

2. Which electrode is placed inside the orifice tube, in coulter counter?
a) Metal electrode
b) Platinum electrode
c) Silicon electrode
d) Magnesium electrode
Answer: b
Clarification: In a coulter counter, a platinum electrode is placed inside the orifice tube and a second electrode is submerged into the beaker containing the cell dilution, creating an electrical circuit between the two electrodes.

3. Which of the following information is not provided by the Coulter Counter?
a) Relative cell size distribution
b) Settings of the threshold level control
c) Relative cell size
d) Mean cell volume
Answer: d
Clarification: The Coulter counters are usually provided with an oscilloscope monitor to display the pulse information, which has passed through the amplifier, and acts as a visible check on the counting process indicating instantaneously any malfunctions such as a blocked orifice. In particular, it provides information regarding (i) relative cell size, (ii) relative cell size distribution, (iii) settings of the threshold level control, and (iv) means to check the performance of the instrument for the reliability of counts.

4. In Coulter counter, for such an aperture, a length of about ______ and flow rate of ______ ml/s would be optimum.
a) 100 u, 0.04
b) 200 u, 0.02
c) 100 u, 0.02
d) 200 u, 0.04
Answer: d
Clarification: Taylor (1970) suggests that an aperture diameter of 100 m would be generally useful. For such an aperture, a length of about 200 μ and flow rate of 0.04 ml/s would be optimum. The aperture can be made using ruby watch jewels bonded to a glass surface.

5. Typically, an aperture of 100 m diameter and 200 m length, separating two solutions of sulphate buffered saline, has a resistance of about 25 kW and capacitance of 120 pF.
a) True
b) False
Answer: b
Clarification: Typically, an aperture of 100 u diameter and 200 m length, separating two solutions of phosphate buffered saline, has a resistance of about 25 kW and capacitance of 120 pF.

6. The required bandwidth of the preamplifier used in cell counter must be?
a) 70 kHz
b) 120 kHz
c) 70 Hz
d) 120 Hz
Answer: a
Clarification: The electronic circuit must have upper frequency response greater than 70 kHz. The preamplifier used in cell counters must be of very low noise preferably having noise voltage less than 2 nA at the required bandwidth of 70 kHz.

7. Which following is not constant for the calibration factor in Coulter counter?
a) Electrolyte resistivity
b) Amplifier gain setting
c) Given aperture size
d) Setting of the threshold level control
Answer: d
Clarification: The calibration factor is constant for given aperture size, electrolyte resistivity and amplifier gain setting. It is used for the conversion of threshold settings to particle volumes or their cube roots to equivalent spherical diameters.

8. What is the diameter of Ragweed pollen?
a) 6 micron
b) 19 micron
c) 14 micron
d) 15 micron
Answer: b
Clarification: Ragweed pollen (19 micron in diameter) and polystyrene latex particles (6–14 micron in diameter) seem to meet these requirements. Of the two, polystyrene latex is preferred for calibration purposes (Thom, 1972). The particles when used seldom plug the orifice. These can be conveniently obtained in the range of 5 million particles per cubic mm.

9. Which of the following is not the provide by multi-parameter coulter counter?
a) Mean cell volume
b) Red cell count
c) Mean cell hemoglobin volume
d) White cell count
Answer: c
Clarification: It provides the universally accepted profile of white cell count, red cell count, mean cell volume, haemotocrit, mean cell haemoglobin concentration, mean cell haemoglobin and haemoglobin. Besides this, the following five parameters are presented: platelet count, red cell distribution width, mean platelet volume, plateletcrit, and platelet distribution width.

10. The diameter of the polystyrene latex particles are ______________________
a) 6 micron
b) 6-20 micron
c) 20 micron
d) 6-14 micron
Answer: d
Clarification: Ragweed pollen (19 micron in diameter) and polystyrene latex particles (6–14 micron in diameter) seem to meet these requirements. Of the two, polystyrene latex is preferred for calibration purposes (Thom, 1972). The particles when used seldom plug the orifice. These can be conveniently obtained in the range of 5 million particles per cubic mm.

11. In multi-parameter coulter counter, what is the time taken by 1 ml of blood to obtain all parameters?
a) 34 sec
b) 45 sec
c) 34-50 sec
d) 34-45 sec
Answer: c
Clarification: All the directly measured parameters are measured in triplicate and the average results are displayed. All the 14 parameters are obtained from 1 ml of whole blood in 34–50 s depending on the number of platelets present.

12. What occurs when two or more particles are present in the sensing zone at the same time?
a) Calibration
b) Troubleshooting
c) Delay in results
d) Coincidence error
Answer: d
Clarification: Coincidence error occurs when two or more particles are present in the sensing zone at the same time. This will result in the instrument detecting fewer particles that are actually present. This will also result in the instrument adding the pulses together to produce a single much longer pulse.

13. Model ____________ automatically compensates for the loss of pulses during coincidence error.
a) 4008 S Coulter counter
b) S plus Coulter counter
c) A plus Coulter counter
d) 4008 A Coulter counter
Answer: b
Clarification: As the instrument detects fewer pulses than are actually present, to render the total count accurate, it is necessary to add on the pulses that have been ‘lost’ due to coincidence. The rate at which this happens has been mathematically determined. Model S-plus Coulter counter automatically compensates for this loss.

14. Under a total count of _______ pulses, primary coincidence is negligible and can be ignored.
a) 5000
b) 1000
c) 8000
d) 10000
Answer: d
Clarification: With some instruments, a correction chart is available to allow the correct number to be determined. Under a total count of 10,000 pulses, primary coincidence is negligible and can be ignored.

15. Coulter counters have a serious drawback linked with the mercury manometer arrangement.
a) True
b) False
Answer: a
Clarification: Coulter counters have a serious drawback linked with the mercury manometer arrangement. The surface of the mercury gets dirty as a consequence of which the contact bordering the volume becomes uncertain, which may make the measured values uncertain.