1. Given a parallel circuit with a constant current source containing resistors of different values, which statement is true?

a. The voltage drop across the less resistive component is the same the ones with higher resistance

b. Current is the same through each resistor

c. The voltage drop across the less resistive component is less than the ones with higher resistance

d. None of the above

2. The conductance of a resistor decreases if the length of the resistor is doubled?

a .True

b. False

6. The total power taken from the power supply and dissipated by the resistors in a series circuit is equal to the sum of the powers dissipated by each resistor in the circuit.

a. True

b. False

7. What is the value of a Green/Brown/Red resistor?

Group of answer choices

a. 5.7 Ω

b .5.1 kΩ

c. 57 kΩ

d. None of the above

8. What is the voltage drop of a load with 100 Ohm that generates 10 mW?

Group of answer choices

a. 1v

b. 10v

c. 10mv

d .None of the above

As shown in below figure, the attenuation of an optical fiber line with the length of 12 km is 2.5 dB/km. The radius of the fiber core is 5 μm. If the optical power at the input of the fiber is 300 μW, what is the output INTENSITY at the output of the fiber?

Derive from the first principles an expression for the reflection coefficient in term of
surge impedance of incident line, Z1 and the transmitted line, Z2.

With the aid of an appropriate circuit, explain the use of potential dividers for
measuring AC high voltages as the measuring method.

1.    When measuring infrared area reflectivity, what is used as a reference material?

a.      Gold

b.     Steel

c.      Silicon

d.     Tungsten

2.    What is true about the light source for photoelectron spectroscopy?

a.      Hit a pure metal with an accelerated electron, resulting in a single-energy X-ray.

b.     The energy of the UV light represents almost constant energy regardless of the discharge gas.

c.      The use of radiation accelerators allows the use of light from various energies.

d.     Monochromator can increase light intensity.

3.    Which of the following statements is incorrect?

a.    Initial state effect is the effect produced by coupling with other atoms/ion.

b.    The initial state effect can be observed to distinguish the chemical species of the specimen.

c.    The Final State effect is the effect caused by the perturbation of the electronic structure by photomultiplier emission.

d.    The Final State effect increases the complexity of the spectra without the information of the samples, causing confusion in the analysis.

4.    Which of the following types of semiconductor-to-semiconductor bonding is advantageous to properly separate the exciton produced after light absorption from the light detector or solar cell?

a.    TYPE I

b.    TYPE II

c.    TYPE III

d.    Not relevant to junction TYPE

5.    What are the advantages of low temperature elliptical spectroscopy?

a.    You can separate overlaid transition points.

b.    Analyze the transition point.

c.    Measure the thickness of the thin film with an accuracy of less than nm.

d.    Accurately measure the level of a valence band

6.    Which of the following statements about XPS, UPS, or IPES is incorrect?

a.    The electronics of valence band cannot be measured with XPS, but must be measured with UPS.

b.    XPS and UPS cannot measure empty electronic structures.

c.    XPS and UPS have the same principle or different energy sources.

d.    IPES measures the energy of photons emitted when electrons are added to a sample.

7.    If the refractive index of the medium between the lens and the focal point is n, and the radius of the lens and the angle between the focal point is a, how is the numerical approach calculated?

a.    n x sina

b.   n x cosa

c.    n x tana

d.   n x cota

8.    A peak appeared in the Photoluminescence spectrum of a direct-gap bulk semiconductor. Which of the following is true?

a.    Band-gap energy is greater than peak energy.

b.   Band-gap energy is smaller than peak energy.

c.    Band-gap energy is the addition of ponon energy to peak energy.

d.   Band-gap energy is the energy of the peak minus the ponon energy.

9.    Which of the following statements is incorrect?

a.    Information on the direction of growth of the crystal structure can be obtained through the Raman spectrometry.

b.    Selection rules for vibration mode are always the opposite in IR spectroscopy and Raman spectroscopy.

c.    In general, the Raman analysis should analyze the light of wavelengths close to incident lasers compared to the luminescence.

d.    Both luminescence (PL) and Raman can be investigated for polarizing dependencies to obtain additional information.

10. Metal reflects most of the terahertz wave, so the transmittance is very low. Why do metals show high reflectivity in the Terahertz area?

a.    electromagnetic reaction of free electron

b.    electromagnetic response of grid oscillation

c.    interband transition phenomenon

d.    various defects in metal

11. Which of the following is the most suitable roadband light source in the range of 300 nm to 700 nm?

a.    Tungsten halogen lamp

b.    Xenon lamp

c.    Mercury lamp

d.    Supercontinuum laser

12. Which dispersion relationship is not suitable for expressing a genetic function with band gaps?

a.    Dielectric function parametric model

b.    Tauc-Lorentz model

c.    Gaussian equation

d.    Lorentz model

13. What is the wavelength area of the medium infrared radiation?

a.    0.1 mm - 10 mm

b.    300μm - 20μm

c.    20μm - 2μm

d.    2μm - 700 nm

14. Which of the following statements is true about Raman Spectrum and the vibration mode of matter?

a.    The Raman Shift value corresponds to the frequency or energy of the vibration mode.

b.    The peak corresponding to all vibration modes appears in the Raman Spectrum.

c.    The strength of each peak in the Raman spectrum is proportional to the crystallinity of the material.

d.    The amorphous material does not produce a Raman signal.

15. What is the energy of a porton with a wavelength of 550 nm?

a.    2.0 eV

b.    2.1 eV

c.    2.2 eV

d.    2.3 eV

16. GaAs were measured with Modulation Spectroscopy. Which of the following statements is incorrect?

a.    The band gap can also be accurately measured at room temperature.

b.    Spin-orbit splitting can be measured.

c.    You can directly measure the curvature of the conditioning band near the point.

d.    Transitions not distinct from the Reflectance spectrum can also be measured.

17. Which of the following is NOT an advantage of terrahertz time-degradation spectrophotometry?

a.    Measurements can be made in a relatively short period of time.

b.    Sensitivity increases because no spectroscopic measurement is performed by dividing energy by frequency.

c.    Because amplitude and phase are determined at the same time, optical constants can be derived without any additional assumptions.

d.    General light sources provide easy access to visible light and ultraviolet areas.

18. When light of linear polarizing is injected into a specimen with a complex dielectric rate, what polarizing is the reflected light generally?

a.    linear polarization

b.    elliptic polarography

c.    circular polarization

d.    rotating polariza

19. Which of the following statements is incorrect?

a.    Initial state effect is the effect produced by coupling with other atoms/ion.

b.     The initial state effect can be observed to distinguish the chemical species of the specimen.

c.    The Final State effect is the effect caused by the perturbation of the electronic structure by photomultiplier emission.

d.    The Final State effect increases the complexity of the spectra without the information of the samples, causing confusion in the analysis.

20. What is NOT a measurement for correct elliptical spectroscopy?

a. Increase the measurement variable by measuring the angle of incidence of multiple angles.

b. Measure only narrow wavelength areas suitable for analysis purposes.

c. Calibration of the optical components must be performed before measuring samples.

d. Prepare a clean sample with a mirror-like.

which circuits must not be connected to any system containing trolley wires with a ground return? a. ground wires b. grounding conductors c.circuits for lighting and power d. ungrounded trolley wires

3) How would you define the number of layers when designing a circuit board? How would you organize them?

For a system with G(s) in forward path and H(s) in feedback path, Derive in details the equivalent transfer function and its zeros/poles?

With the advent of capacitive touch sensors the human body capacitance has an ever incresing role to play in the design of touch screens, switches etc. Besides ESD (electrostatic discharge ) from and to the human body from various electronics devices and gadgets is important for EMC (electromagnetic compatibility) of the gadgets. Your assignment is to estimate the range of human body capacitance. Give detailed justification for your method of estimation. Compare your estimates to available/published data sheets.

Show what happens when the symmetry is not imposed in FIR filters. what happens to the linear phase?

9. Which of the following statements is FALSE? I. The efficiency of a heat engine has no units II. The coefficient of performance of a heat pump has no units III. The coefficient of performance can be less than 1 IV. The Carnot efficiency of a heat engine can be increased by decreasing the temperature difference between the cold and hot reservoir a. I and II b. II and III c. Only III d. III and IV e. II and IV

A three phase engine has an usable power of 90 kW and an efficiency of 91%. The rating plate indicates the following values:
- 90 kW
- Power factor: 0.89 (i)
- Voltage (volts): 230 delta - 400 wye
Taking as a reference of line voltages V1=V∠90º; direct sequence and a phase oltage of the supply network of 230 V, find:
a) The phasors of the line and phase voltages of the supply network
b) The true, reactive and apparent power
c) The phasors of the line and phase currents
When the engine is connected to a supply network of 400 V and direct sequence, find:
d) The phasors of the line and phase voltages of the supply network
e) The true, reactive and apparent powers
f) The phasors of the line and phase currents

Write the Pros and cons of the second and third generation of the solar photovoltaic cells.