How can the resolution of the collimator be increased?
1.By reducing the separation between the metal plates of the collimator
2.By increasing the separation between the metal plates of the collimator
3.By increasing the number of metal plates
4.By decreasing the number of metal plates
If number of channels is more than ten, the problems of stability of discrimination voltages arise.
1.True
2.False
3.all of the above
4.None of the mentioned
In liquid scintillation counter, which of the following is a fluorescent substance?
1.Solvent
2.Solute
3.Crystal
4.Reagent
In which type of quenching, the radiation emitted by the isotope is not detected due to absorption of the radiation by the sample itself?
1.Chemical quench
2.Interference quench
3. Colour quenching
4.Self-absorption
The first gamma camera is also known by which of the following names?
1.Hal camera
2.Anger camera
3.Muller camera
4.West camera
The pulses having amplitudes between the two triggering levels are given by which of the following components?
1.Pre-amplifiers
2.Linear amplifiers
3.Anti-coincidence circuits
4.Discriminators
Using which of the following components is the generated x-rays focussed upon the specimen?
1. X-ray tube
2.Monochromator
3. Collimator
4.Detector
When UV light is absorbed by the fluor molecules the light emitted is in which of the following colours?
1.Pink
2. Red
3.Green
4. Blue
Which of the following components cancels all the pulses which trigger both the discriminators?
1.Pre-amplifier
2. Linear amplifier
3.Anti-coincidence circuit
4. Discriminator
X-ray diffractometers are not used to identify the physical properties of which of the following?
1.Metals
2. Liquids
3.Polymeric materials
4.Solids
X-ray diffractometers provide ____________ information about the compounds present in a solid sample.
1.Quantitative
2.Qualitative
3.Quantitative and qualitative
4.Either quantitative or qualitative
A discriminator circuit is which of the following circuits?
1.Wheatstone bridge
2.Instrumentation amplifier
3.Astable multivibrator
4.Schmitt trigger
A quench curve can be constructed by plotting the counting efficiency versus _________
1.Q-number
2. Quench factor
3. H-number
4.Disintegrations
Diffractometers are similar to which of the following?
1. Optical grating spectrometer
2.Prism spectrometer
3.Photo multiplier
4.Photovoltaic cell as detector
Due to the presence of red, green and yellow colour in the vial, which of the following occurs?
1. Chemical quench
2. Interference quench
3. Colour quenching
4.Self-absorption
Gamma camera uses one scintillation detector.
1. True
2. False
3.all of the above
4.None of the mentioned
Gamma camera uses which of these components to produce a position intensity picture of a radioactive area?
1.Collimator
2.Scintillation detector
3.Photo multiplier tubes
4. Position circuitry
In Diffractometer, the identification of a component of the sample from its powder diffraction pattern is based upon the _________ of lines and their relative _______
1.Number, length
2.Number, intensity
3.Position, length
4. Position, intensity
In liquid scintillation counter, which of the following is used to convert light into electrical signals?
1.Photo multiplier tube
2.Photo emissive tube
3.Photo voltaic cell
4.Photo reflector
In powder method, the powder sample is contained in which of the following?
1. Thin walled glass capillary tubes
2.Thin walled test tube
3.Thin walled curvettes
4.Thin walled flask
In X-ray spectrometers, the specimen or the sample is placed after which of the following components?
1.X-ray tube
2. Monochromator
3. Collimator
4.Detector
Photomultipliers used in Liquid scintillation detectors are a source of instability.
1.True
2. False
3.all of the above
4.None of the mentioned
Schmitt triggers are followed by which of the following components?
1.Pre-amplifier
2.Linear amplifier
3.Anti-coincidence circuit
4.Discriminators
Straight bore collimator is used for thyroid work in the medical field.
1.True
2.False
3.all of the above
4.None of the mentioned
The cathode in the Coolidge tube is kept in an inclined manner.
1.True
2.False
3.all of the above
4.None of the mentioned
The cathode in the Coolidge tube is made of which of the following elements?
1.Quartz
2. Iron
3. Tungsten
4.Barium
The difference between the pulses having amplitudes between the two triggering levels is called ______
1. Pulse width
2.Energy gap
3.Window width
4. Amplitude variation
The measurement of pulse height is useful for energy determination.
1.True
2. False
3.all of the above
4.None of the mentioned
The reduction in counting efficiency of the scintillation detector is called as ______
1.Disintegration
2. Decay
3.Quenching
4.Reduction
The signal reaching which of the following components is the one lying in the window of pulse height analyser?
1.Pre-amplifier
2.Linear amplifier
3.Counter
4.Discriminators
The x-rays generated come out of the Coolidge tube through which of the following?
1. Beryllium window
2.Tungsten window
3.Collimator
4.Target material
Using the powder method of diffractometers, which of the following can be determined?
1.Percentage of K+
2.Percentage of Na+ and Cl-
3.Percentage of KBr and NaCl
4.Percentage of Br-
Variation of gain with temperature does not cause instability.
1. True
2. False
3.all of the above
4.None of the mentioned
When certain geometric requirements are met, X-rays scattered from a crystalline solid can constructively interfere with each other and produce a diffracted beam.
1.True
2.False
3.all of the above
4.None of the mentioned
When compared to filters, monochromators provide much signal to noise ratio.
1.True
2.False
3.all of the above
4.None of the mentioned
When the energy of an absorbed gamma photon is released, a flash of light is produced. This is similar to which of the following effects?
1. Photoelectric effect
2.Compton effect
3.Pair production
4.Collision effect
When x-rays emitted from molybdenum are allowed to pass through a zirconium filter, which of the following occurs?
1. It absorbs radiation of shorter wavelength
2.It absorbs radiation of longer wavelength
3.It allows radiation of shorter wavelength to pass through
4.It allows radiation in a particular band to pass through
Which of the following components adds all the signals and determines where each scintillation event occurred in the detector?
1.Collimator
2.Detector crystal
3.Photo multiplier tubes
4.Position circuitry
Which of the following components are used to generate X-rays?
1.Meyer tube
2.West tube
3.Anger tube
4.Coolidge tube
Which of the following crystals are not suited for x-ray grating?
1.Topaz
2.Lithium fluoride
3.Calcium fluoride
4.Sodium fluoride
Which of the following is a pattern of holes through gamma ray absorbing material, usually lead or tungsten?
1.Collimator
2.Detector crystal
3.Photo multiplier tubes
4.Position circuitry
Which of the following is known as a scintillation counter?
1. Scintillator
2.Scintillator along with a photo multiplier tube
3. Scintillator along with the crystal
4.Scintillator along with position circuitry
Which of the following is not a component of gamma camera?
1.Collimator
2.Detector crystal
3.Pre-amplifier
4.Position logic circuit
Which of the following is not a target metal used in the Coolidge tube?
1.Rhodium
2.Cobalt
3.Gold
4.Silver carbide
Which of the following is not a type of quenching?
1.Chemical quench
2.Interference quench
3.Colour quenching
4.Self-absorption
Which of the following is the first object that an emitted gamma photon encounters after exciting the body?
1.Collimator
2. Detector crystal
3.Photo multiplier tubes
4.Position logic circuit
Which of the following is the function of the discriminator?
1.Rejects signals below a certain voltage
2.Rejects signals above a certain voltage
3.Rejects signal in a range alone
4.Filters noise alone
Which of the following is the most common instrument for photographic recording of diffraction patterns?
1. Debye-Scherrer powder camera
2.Gamma camera
3. Geiger tube
4. Scintillation counter
Which of the following is used when the number of channels is ten or less?
1.Two discriminators in series
2.Two discriminators in parallel
3.Series array of discriminators
4.Parallel array of discriminators
With the help of which of the following equations is the distance calculated from a known wavelength of the source and measured angle?
1.Coolidge equation
2.Bragg’s equation
3. Debye equation
4.Scherrer equation