Test
Transformation of non-electrical quantities. Calibration of semiconductor, thermometer and photoelement - Medical Physics - MCQs
Preguntas del test (24)
1If a semiconductor is brought down to temperature of absolute zero (0 Kelvin), it will become:
- AA conductor
- BA superconductor
- CAn insulator
2According to Band Theory of Solids, what can be said about the relationship between band-gap width and the tendency of material to conduct electricity?
- AThe greater the band-gap width the less conductive is the material
- BThe lesser the band-gap width the more insulating is the material
- CThe greater the band-gap width the more conductive is the material
3According to Band Theory of Solids, what can be said about P- and N- type conductivity with regard to the location of the electron bands?
- AP and N type conductivities are in the conduction band
- BP-type conductivity is in the conduction band, and N-conductivity is in the valence band
- CP-type conductivity is in the valence band, and N-conductivity is in the conduction band
4What are the respective current carriers for N- and P-type conductivity?
- AElectrons
- BP-type carriers are “holes”, and N-type are electrons
- CP-type are positrons, and N-type are “holes”
5Typical semiconductors such as Silicon and Germanium are group IV elements. Choose the correct statement regarding the doping and the type of conductivity (N or P) acquired, after doping:
- AP-type conductivity is achieved by doping with elements from group V, and N-type conductivity is achieved by doping with elements from group III
- BBoth types are achieved from doping with group IV
- CP-type conductivity is achieved by doping with elements from group III, and N-type conductivity is achieved by doping with elements from group V
6What is the relationship between N- and P- type charge carriers for intrinsic (undoped) semiconductors?
- AN = P
- BN > P
- CN < P
7For semiconducting materials, charge carrier species called holes are best described as:
- AElectrons moving in opposite direction
- BProtons
- CVirtual particles signifying electron vacancy
8In doped (extrinsic) semiconductors, the predominant current carriers are called majority charge carriers, and secondary carriers are called minority. Which statement is true for N-and P-type semiconductors:
- AIn N-type semiconductors, electrons are majority carriers and holes are minority carriers
- BIn P-type semiconductors, majority carriers are electrons, and minority charge carriers are holes
- CIn N-type semiconductors, both types of carriers are equally present
9Transistors are made of N- and P-type semiconductors arranged in a such way that:
- AThere are two p-n junctions
- BThere are three p-n junctions
- CThere is one p-n junction
10The two main functions of the transistor are:
- APolarizer and oscillator
- BAmplifier and switch
- CRectifier and attenuator
11Choose the FALSE statement. Electrical amplifiers are used for:
- AVoltage
- BFrequency
- CCurrent
12The magnitude of electrical impedance of biological tissues is the (Pythagorean) sum of:
- AResistance and capacitive reactance
- BInductive and capacitive reactance
- CResistance and inductive reactance
13What type of transducer is the piezoelectric crystal in ultrasonic equipment, when working in receiving mode?
- AGenerative transducer
- BBoth, generative and parametric
- CParametric transducer
14The “band gap” in semiconductor theory is defined as:
- AThe distance between valence and conduction bands
- BThe frequency gap between AM and FM radio bands
- CThe energy gap between valence and conduction bands
15When temperature increases, the band gap in a semiconductor:
- AIncreases, due to increased kinetic energy of atoms
- BRemains the same, because electrons are bound in their orbits
- CDecreases, due to electron-phonon interactions
16When semiconductor is doped with element of lower valence (P-type doping) it becomes a donor (gives off electrons) and there is a shift in the energy band gap. The new electron levels are:
- ANear the middle of the band gap
- BNear the conduction band
- CNear the valence band
17When temperature increases, the conductivity of semiconductors:
- AIncreases
- BDecreases
- CRemains the same
18When semiconductor is doped with element of higher valence (N-type doping) it becomes an acceptor (takes electrons) and there is a shift in the energy band gap. The new electron levels are:
- ANear the middle of the band gap
- BNear the conduction band
- CNear the valence band
19When Silicon (Si) is doped with one of the following elements, it acquires P-type conductivity (holes are the majority carriers). Choose the one:
- ABoron (B), valence III
- BPhosphorus (P), valence V
- CTin (Sn), valence IV
20Electric circuit components composed of single p-n junction are called:
- ACapacitors
- BTransistors
- CDiodes
21What is the mathematical relation between the electrical resistance (R) in a semiconductor and the temperature (T)?
- ALinear (as T increases, R decreases with constant rate)
- BProportional (as T increases, R increases with constant rate)
- CExponential decay (as T increases, R decreases with increasing rate)
22What is the mathematical relationship between the generated voltage in a photodiode and the distance from the light source?
- AQuadratic (voltage increase as the square of the distance)
- BInversely proportional (decreases as one over the distance)
- CExponential (increases with increasing rate)
23Which of the following statements is true about the element Germanium?
- AThe resistivity at room temperature is lower than that of Copper
- BWhen heated the resistivity decreases
- CThe resistivity is constant over a wide range
24The most common material in modern integrated circuits is:
- ASilicon
- BCarbon
- CTitanium
Información
- Descripción
- Medical Physics Test sobre Transformation of non-electrical quantities. Calibration of semiconductor, thermometer and photoelement - Medical Physics - MCQs, creado por Hussain Basheer el 23/11/2018.
- Autor
- Hussain Basheer
- Idioma
- English
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