Multiple choice question for engineering
Set 1
1. Which of the following is the full scale range of Infrared spectroscopy method used for measurement of carbon monoxide?
a) 0-2 ppm
b) 0-500 ppm
c) 0-1 ppm
d) 0-50 ppm
Answer
Answer: d [Reason:] The full scale range of Infrared spectroscopy method used for measurement of carbon monoxide is 0-50 ppm. It depends on the characteristic absorption of CO molecule at a particular wavelength.
2. Which of the following is the full scale range of Gas chromatography method used for measurement of carbon monoxide?
a) 0-200 ppm
b) 0-500 ppm
c) 0-1 ppm
d) 0-50 ppm
Answer
Answer: a [Reason:] The full scale range of Gas chromatography method used for measurement of carbon monoxide is 0-200 ppm. The detector used in this method is flame ionization detector.
3. Which of the following are not the characteristics of Non-dispersive infrared analyzer method?
a) Easy to maintain
b) High response speed
c) Effect of interfering components is high
d) High sensitivity
Answer
Answer: c [Reason:] Effect of interfering components is small for Non-dispersive infrared analyzer method. It depends on the characteristic absorption of CO molecule at a particular wavelength.
4. Non-dispersive infrared analyzer depends on the characteristic absorption of CO molecule at a wavelength of __________
a) 5.4 µm
b) 4.6 µm
c) 8.9 µm
d) 10.8 µm
Answer
Answer: b [Reason:] Non-dispersive infrared analyzer depends on the characteristic absorption of CO molecule at a wavelength of 4.6 µm.
5. The zero of the scale is calibrated using which of the following as the sample?
a) Air
b) Water
c) Inert gas
d) Pure nitrogen
Answer
Answer: d [Reason:] The zero of the scale is calibrated using pure nitrogen as the sample. Optical filters are used to minimize effects of interfering gases.
6. The disadvantage of Non-dispersive infrared analyzer is that the effect of flow rate is large.
a) True
b) False
Answer
Answer: b [Reason:] In Non-dispersive infrared analyzer, the effect of flow rate is small. Optical filters are used to minimize effects of interfering gases.
7. A stripper column used in gas chromatography, can be used to retain which of the following when an air sample is passed through it?
a) CO
b) Methane
c) Light hydrocarbons
d) Heavy hydrocarbons
Answer
Answer: d [Reason:] A stripper column can be used to retain heavy hydrocarbons when an air sample is passed through it. It passes CO and methane into the column.
8. Which of the following is not a component of the mixture present in the reference cell of Non-dispersive infrared analyzer?
a) CO
b) Nitrogen
c) Water vapour
d) Hydrogen
Answer
Answer: d [Reason:] The reference cell contains a fixed quantity of gases. It contains CO, nitrogen and water vapour.
9. Hydrogen flame ionization detector can be used to detect only the peak of CO and not methane.
a) True
b) False
Answer
Answer: b [Reason:] Hydrogen flame ionization detector can be used to detect the peak of both CO and methane. The accuracy is about 2%.
10. CO analyzers based on infrared absorption would give greater sensitivity under which of the following conditions?
a) With larger cell path lengths
b) With smaller cell path lengths
c) By changing the gases in the reference cell
d) By increasing the sample flow rate
Answer
Answer: a [Reason:] CO analyzers based on infrared absorption would give greater sensitivity with larger cell path lengths. If 1m path length is given, the range is from 0 to 50ppm.
Set 2
1. Which of the following methods cannot be used for the estimation of hydrocarbons?
a) Mass spectroscopy
b) Chemiluminescence method
c) Ultraviolet absorption
d) Gas chromatography
Answer
Answer: b [Reason:] Chemiluminescence method cannot be used for the estimation of hydrocarbons. This is because hydrocarbons do not produce chemiluminescence effect.
2. Which of the following is the most abundant hydrocarbon which is emitted into the atmosphere by biological activity?
a) Ethane
b) Methane
c) Poly Aromatic hydrocarbons
d) Pentane
Answer
Answer: b [Reason:] The most abundant hydrocarbon which is emitted into the atmosphere by biological activity is methane. It is also emitted by automobile exhausts, burning of coal, etc.
3. Flame ionization detectors are sensitive to which of the following gases?
a) Carbon dioxide
b) Methane
c) Carbon monoxide
d) Sulphur dioxide
Answer
Answer: b [Reason:] Flame ionization detectors are sensitive to methane since, they are sensitive to organic compounds. They are insensitive to non-combustible gases. Hence, they are not sensitive to carbon monoxide, carbon dioxide and sulphur dioxide.
4. How can carbon monoxide be detected using flame ionization detectors while using gas chromatography technique?
a) By converting it into carbon di-oxide
b) By converting it into methane
c) By mixing it with combustible gases
d) It cannot be detected
Answer
Answer: b [Reason:] Carbon monoxide cannot be detected directly using flame ionization detectors while using gas chromatography technique. Hence, it is converted into methane and is then detected.
5. Which of the following organic compounds will have the highest intensity of response when introduced in a flame ionization detector?
a) Methane
b) Ethane
c) Propane
d) Butane
Answer
Answer: d [Reason:] Butane will have the highest intensity of response when introduced in a flame ionization detector. This is because the intensity of response will be in proportion with the number of carbon atoms in the chain.
6. Propane would give three times the intensity of response as compared to methane.
a) True
b) False
Answer
Answer: a [Reason:] Propane would give three times the intensity of response as compared to methane. This is because the intensity of response will be in proportion with the number of carbon atoms in the chain.
7. In flame ionization detectors, which of the following is the range adequate for atmospheric sampling?
a) 0-1 ppm
b) 0-2 ppm
c) 0-20 ppm
d) 0-100 ppm
Answer
Answer: c [Reason:] In flame ionization detectors, the range adequate for atmospheric sampling is 0-20ppm. It is useful for detecting organic compounds.
8. Which of the following methods make use of pyrolysis while used for detecting methane?
a) Mass spectroscopy
b) Flame ionization detector
c) Ultraviolet absorption
d) Gas chromatography
Answer
Answer: b [Reason:] Flame ionization detector makes use of pyrolysis while used for detecting methane. It is used to detect organic compounds.
9. In flame ionization detector, the ions collected on the negatively charged grid are amplified at the high impedance amplifier.
a) True
b) False
Answer
Answer: b [Reason:] In flame ionization detector, the ions collected on the positively charged grid are amplified at the high impedance amplifier. Its output is given to the chart recorder.
10. Which of the following is not the characteristic of flame ionization detector?
a) Good linearity
b) Narrow range of concentration
c) High sensitivity
d) Fast response
Answer
Answer: b [Reason:] Narrow range of concentration is not the characteristic of flame ionization detector. It has a broad range of concentration.
Set 3
1. Fourier transform NMR spectrometer allows NMR transitions to be observed simultaneously.
a) True
b) False
Answer
Answer: a [Reason:] Fourier transform NMR spectrometer is a type of NMR spectrometer. It allows samples to be observed simultaneously instead of serially.
2. Fourier transform NMR spectrometer has which of the following characteristics?
a) Increased sensitivity, long time to obtain data
b) Decreased sensitivity, long time to obtain data
c) Increased sensitivity, reduced time to obtain data
d) Decreased sensitivity, reduced time to obtain data
Answer
Answer: c [Reason:] Fourier transform NMR spectrometer has increased sensitivity. It takes less time to obtain NMR data.
3. Which of the following cannot be done due to the multiplex advantage?
a) Repetitive signals can be summed
b) Repetitive signals can be averaged
c) Increases signal to noise ratio
d) Decreases signal to noise ratio
Answer
Answer: d [Reason:] The multiplexing advantage allows improvement of the signal to noise ratio. It also allows repetitive signals to be summed and averaged.
4. Two coils are necessary in Fourier transform NMR spectroscopy.
a) True
b) False
Answer
Answer: b [Reason:] Only one coil is necessary in Fourier transform NMR spectroscopy. The coil serves as both antenna for transmitting and receiving RF radiation.
5. Which of the following is the disadvantage of conventional mode of spectrometer or continuous-wave NMR spectrometer?
a) They are unstable
b) Maintenance is difficult
c) High operating cost
d) Excitation is inefficient
Answer
Answer: d [Reason:] The disadvantage of conventional mode of spectrometer or continuous-wave NMR spectrometer is that the excitation is inefficient. Only a narrow band of frequencies are contributing to the signal at a time.
6. Which of the following must be done to improve sensitivity?
a) Frequency sweep mode must be preferred
b) Field sweep mode must be preferred
c) Single channel excitation must be preferred
d) Multichannel excitation must be preferred
Answer
Answer: d [Reason:] Sweep techniques have less sensitivity. To improve sensitivity, multichannel excitation must be preferred.
7. Which of the following is the disadvantage of multichannel excitation?
a) Low sensitivity
b) Low resolution
c) Small number of frequencies is present
d) Uneconomical
Answer
Answer: d [Reason:] Large number of frequencies is present in multichannel excitation. This is uneconomical since a receiver is required for each channel.
8. How can the need for array of narrow-band filters and detectors be eliminated?
a) By using multi-channel excitation
b) By using a detector for each frequency
c) By reducing the number of detectors
d) By using Fourier transform
Answer
Answer: d [Reason:] Fourier transform plays the role of multichannel receiver. Hence, the need for array of narrow-band filters can be eliminated
9. Fourier transform can be accomplished by using which of the following components?
a) Spin decoder
b) Detector
c) Spectrum analyser
d) Oscilloscope
Answer
Answer: c [Reason:] Fourier transform can be accomplished by using spectrum analyser. Any complex waveform can be converted to frequencies using Fourier transform.
10. A 15.4 MHz crystal generates the _________ resonance frequency?
a) Hydrogen
b) Deuterium
c) Tritium
d) Helium
Answer
Answer: b [Reason:] A 15.4 MHz crystal generates the deuterium resonance frequency. This resonance signal is used to lock the magnetic signal to clock frequency.
Set 4
1. Which of the following are highly effective in producing ion pairs when they pass through the matter?
a) Alpha particles
b) Beta particles
c) Gamma particles
d) X-ray particles
Answer
Answer: a [Reason:] Alpha particles are highly effective in producing ion pairs when they pass through the matter. They have relatively large mass and charge.
2. Which of the following can liberate photo electrons when they fall on certain metals?
a) Alpha particles
b) Beta particles
c) Gamma particles
d) X-ray particles
Answer
Answer: d [Reason:] X-rays can liberate photo electrons when they fall on certain metals. They penetrate through certain substances that are opaque to ordinary light.
3. Which of these particles are highly penetrating?
a) Alpha particles
b) Beta particles
c) Gamma particles
d) X-ray particles
Answer
Answer: c [Reason:] Gamma particles are highly penetrating. Upon interaction with matter, they lose energy in three modes.
4. Alpha emission is characteristic of heavier radioactive elements such as thorium, uranium, etc.
a) True
b) False
Answer
Answer: a [Reason:] Alpha emission is characteristic of heavier radioactive elements such as thorium, uranium, etc. They are most harmful to the human tissue.
5. Which of the following is not a mode by which beta particles lose energy on interaction with matter?
a) Photoelectric effect
b) Compton effect
c) Pair production
d) Collision effect
Answer
Answer: d [Reason:] Upon interaction with matter, gamma rays lose energy in three modes. They are photoelectric effect, pair production and Compton Effect.
6. The stability of the nucleus can be predicted by which of the following?
a) Electron to neutron ratio
b) Neutron to proton ratio
c) Proton to electron ratio
d) Neutron to electron ratio
Answer
Answer: b [Reason:] The stability of the nucleus can be predicted by neutron to proton ratio. The number of protons will always be equal to the number of electrons.
7. Which of the following is true about radiochemical methods?
a) Eliminate the need for chemical preparation
b) Not sensitive
c) Not accurate
d) Not specific
Answer
Answer: a [Reason:] Radiochemical methods eliminate the need for chemical preparation. In other method, chemical preparation has to be done before the measurement.
8. Which of the following formulae gives the expression for half-life of a radioactive isotope when ‘λ’ is the decay constant?
a) 0.762/λ
b) 0.693/λ
c) 0.937/λ
d) 0.258/λ
Answer
Answer: b [Reason:] The formula to calculate half-life of a radioactive isotope is 0.693/λ. It is the time required for half the initial stock of atoms to decay.
9. Which of the following emissions have low ionizing power?
a) Alpha particles
b) Beta particles
c) Gamma particles
d) X-ray particles
Answer
Answer: c [Reason:] Gamma particle emissions have low ionizing power. They also have high penetrating power.
10. Which of the following effect occurs when a gamma ray and an electron make an elastic collision?
a) Photoelectric effect
b) Compton effect
c) Pair production
d) Collision effect
Answer
Answer: d [Reason:] Upon interaction with matter, gamma rays lose energy in three modes. Compton effect occurs when a gamma ray and an electron make an elastic collision.
11. Which of the following effects transfers all the energy of the gamma ray to an electron in the inner orbit of the atom of the absorber?
a) Photoelectric effect
b) Compton effect
c) Pair production
d) Collision effect
Answer
Answer: a [Reason:] Upon interaction with matter, gamma rays lose energy in three modes. Photoelectric effect transfers all the energy of the gamma ray to an electron in the inner orbit of the atom of the absorber.
12. The basic unit used to describe the energy of a radiation particle is curie.
a) True
b) False
Answer
Answer: b [Reason:] The basic unit used to describe the energy of a radiation particle is electron volt (eV). The unit of radioactivity is curie.
Set 5
1. The first gamma camera is also known by which of the following names?
a) Hal camera
b) Anger camera
c) Muller camera
d) West camera
Answer
Answer: b [Reason:] The first gamma camera is also known as Anger camera. It was developed by Hal Anger.
2. Which of the following is not a component of gamma camera?
a) Collimator
b) Detector crystal
c) Pre-amplifier
d) Position logic circuit
Answer
Answer: c [Reason:] Pre-amplifier is not a component of gamma camera. It is an imaging device commonly used in medical applications.
3. Which of the following is the first object that an emitted gamma photon encounters after exciting
the body?
a) Collimator
b) Detector crystal
c) Photo multiplier tubes
d) Position logic circuit
Answer
Answer: c [Reason:] Collimator is the first object that an emitted gamma photon encounters after exciting the body. In the conventional method, the collimator is placed over the detector crystal.
4. Which of the following is a pattern of holes through gamma ray absorbing material, usually lead or
tungsten?
a) Collimator
b) Detector crystal
c) Photo multiplier tubes
d) Position circuitry
Answer
Answer: a [Reason:] Collimator is a pattern of holes through gamma ray absorbing material, usually lead or tungsten. In the conventional method, the collimator is placed over the detector crystal.
5. When energy of an absorbed gamma photon is released, a flash of light is produced. This is similar to which of the following effects?
a) Photoelectric effect
b) Compton effect
c) Pair production
d) Collision effect
Answer
Answer: a [Reason:] The given effect is similar to photoelectric effect. It occurs in scintillation detector.
6. Which of the following components adds all the signals and determines where each scintillation event occurred in the detector?
a) Collimator
b) Detector crystal
c) Photo multiplier tubes
d) Position circuitry
Answer
Answer: d [Reason:] Position circuitry adds all the signals and determines where each scintillation event occurred in the detector. It is an electronic circuit and it receives all the signals from photo multiplier tube.
7. Gamma camera uses one scintillation detector. Is this statement true or false?
a) True
b) False
Answer
Answer: b [Reason:] Gamma camera uses multiple scintillation detectors. Hence, it is also known as scintillation camera.
8. Gamma camera uses which of these components to produce a position intensity picture of radioactive area?
a) Collimator
b) Scintillation detector
c) Photo multiplier tubes
d) Position circuitry
Answer
Answer: b [Reason:] Gamma camera uses scintillation detector to produce a position intensity picture of radioactive area. It is an imaging device commonly used in medical applications.
9. Which of the following is known as a scintillation counter?
a) Scintillator
b) Scintillator along with a photo multiplier tube
c) Scintillator along with the crystal
d) Scintillator along with position circuitry
Answer
Answer: b [Reason:] Scintillation detector along with a photo multiplier tube is known as scintillation counter.Scintillation is the process of turning radioactive energy into light using a scintillator.
10. Straight bore collimator is used for thyroid work in medical field. Is this statement true or false?
a) True
b) False
Answer
Answer: b [Reason:] Straight bore collimator is used for liver, brain, etc. Pinhole collimator is used for thyroid work.