ESAS 3.1
問題一覧
1
The basic reason why a full wave rectifier has twice the efficiency of a half wave rectifier is that
It utilizes both half cycle of the input
2
Which stage of a DC power supply uses zener diode as the main component
Regulator
3
A live room one whose interior finishing is such that reverbation time of sound is
less than 1
4
which of the following logic circuits is the fastest
transistor-transistor-logic (TTL)
5
The gate voltage in a FET at which the drain current Id becomes zero is called
pinch off voltage
6
The main factor which differentiates a DE MOSFET from E-only MOSFET is the absence of:
electrons
7
what electrode in a junction transistor corresponds to the cathode in a vacuum tube?
emitter
8
If the power level of an amplifier reduces to one-half, the dB gain will fall by.
3 dB
9
Piezoelectricity principle is applied in one of the following
Thermometer
10
In 1885, he used a long wire as antenna and developed a practical radio system
Marconi
11
It refers to a device that merely boosts a signal and passes it on
Repeater
12
RJ45 is used for.
Data
13
What is the most common fiber of the cable
Multi mode step index
14
What is the function of a transducer
Energy conversion
15
How many doped regions does a typical bipolar Junction transistor (BJT) have?
Three
16
An amplifier with a feedback loop or path for energy to propagate from the output back to the input is.
Regenerative feedback
17
Is the depletion region in a junction died forms what part of capacitor
Dialectric
18
Increasing the reverse bias on a varactor diode will cause its capacitance
Increase
19
What is the SI unit of thermodynamic temperature
Kelvin
20
Relative dialectic strength of gases tend with increasing molecular weight
Upward
21
Which of the following is the usual geometric view factor for a black body
One
22
Loudness of sound proportional to the square of
Amplitude
23
What is the maximum frequency which the human ear can hear
20,000 hz
24
Electromagnetic waves are refracted when they
Pass into a medium of different dialectric constant
25
The emission of electrons from matter by electromagnetic radiation of certain energy is
Photoelectric effect
26
The ratio of electric flux density to electric field intensity is called _____ of the medium
Permitivity
27
Wave propagation in perfect dialectric occurs
Without attenuation
28
For a perfect match between transmission line and load, the value of reflection coefficient should be
zero
29
The electromagnetic and electrostatic fields radiated by an antenna are out of phase by
90°
30
The physical relationship of gaseous system is treated by _______ of gases in which their properties are related to P, V and T of system
Kinetic theory
31
What is the branch of physics that deals with the dynamic property of gases
Pneumatics
32
The particle inside the nucleus is called
Nucleons
33
What do you call the nucleus a specific isotope of an element
Nuclide
34
If 1 g of matter could be converted entirely to energy, what would be the value of the energy to produce in kWh?
25x10^6
35
When the distance between two charges is doubled, the force between them will be equal to
One fourth
36
Which of the following laws of electromagnetic theory is connected with the force experience by two loops of a wire carrying a current
Ampere
37
____ is a scaler quantity
Potential in electric field
38
Steepness of the traveling waves in transmission line is attenuated by _____ of the line
Resistance
39
The absorption of radio waves by the atmosphere depends on which of the following
Frequency
40
The polarization of dialectric materials results in
Creation of electric dipole
41
Polarization of an electromagnetic wave is
The direction of its electric field component with respect to ground
42
A plane electromagnetic wave travels in a dialectric medium of relative permitivity of 9. Relative to free space, what is the velocity of propagation in the dielectric?
Reduce by a factor of one third
43
In transmission line the ratio of reflected power to incident power is given by
r2
44
Fundamental purpose is the transfer information from one electronic place to another
Electronic communication system
45
A collection of one or more electronic devices or circuits that converts the original source information to a form more suitable for transmission over a particular transmission medium
Transmitter
46
The process of changing one or more properties of the analog carrier in proportion with the information signal
Modulation
47
A modulation technique where the information signal is analog and the amplitude of the carrier is varied proportional to the information signal
AM
48
A specific band of frequencies allocated to a particular service
Channel
49
Signals in the 3 GHz to 30 GHz range and include the majority of the frequencies used for microwave and satellite radio communication systems.
SHF
50
The difference between the highest and lowest frequencies contain in the information
Bandwidth
51
The _____ of a waveform consists of all the frequencies contain in the wave form and their respective amplitude plotted in the frequency domain
Frequency spectrum
52
Noise can be reduced by
Narrowing the bandwidth
53
The ____ occurs when oscillating mechanical stresses applied across a crystal lattice structure. Generated electrical oscillations in vice versa.
Piezoelectric effect
54
The first stage of the receiver of which primary functions are detecting, band limiting and amplifying the received RF signal
RF section
55
The process of combining transmission from more than one source and then transmitting them over a common facility such as metallic or optical fiber cable or a radio frequency
multiplexing
56
A form of amplitude modulation in which the carrier is transmitted at full power, but only one of the sidebands is transmitted
SSBFC ( Single side band full carrier)
57
Half-duplex, one to many radios communication with two way no dial tone
Two way mobile radio
58
The ratio of the peak modulating signal voltage to the peak carrier voltage is
Modulation index
59
The operation of a fiber-optic cable is based on the principle of
Reflection
60
The core of the fiber-optic cable is surrounded by
Cladding
61
The electromagnetic waves produced primarily by heat are called
Infrared rays
62
Another name for signals in the HF range is
Short waves
63
Which color has the shortest wavelength of light
Blue
64
Electronic communications was discovered in which century?
19th
65
If the amplitude of the modulating signal applied to a phase modulator is constant, the output signal will be
carrier frequency
66
The TV signal uses which type of modulation for picture and sound respectively?
AM, FM
67
Random interference to transmitted signals is called
noise
68
The communication medium causes the signal to be
attenuated
69
Distortion of the modulating signal produces harmonics which cause an increase in the signal
bandwidth
70
The process of translating a signal with or without modulation to a higher or lower frequency for processing is called
Frequency conversion
71
How many pins comprise the RS232C
25
72
In a radio receiver, noise is generally developed at
RF Stage
73
It is the high frequency sound that cannot be heard by human ear.
ultrasonic
74
the number of frames per second in the Philippine television system is
30
75
What is the light source typically used in multimode optical fiber
LED
76
which of the following is a unit of information
dit
77
the most accurate type of test equipment used for measuring high power is the
bolometer
78
GSM has a fixed bit rate of
270 Kbps
79
bluetooth operates in what frequency
2.5 GHz
80
Simultaneous two-way communicatipns is called
full duplex
81
A display of signal amplitude versus frequency is called
frequency domain
82
Are signals in the 0.3 THz to 300 THz range and are not generally referred to as radio waves. Used in heat seeking guidance systems, electronic photography, and astoronomy
infrared
83
a signal that repeats at a uniform rate
periodic wave
84
It is a solid transparent fiber of flass or polymer that carries an optical signal
fiber optic
85
Are voltage or current that change in discrete steps or levels
digital signal
86
A modem converts
Both analog signals to digital and digital signals to analog signals
87
Any undesirable electrical energy that falls within the pass band of the signal
Electrical noise
88
Overmodulation results in
distortion
89
Demodulation is done in
radio receiver
90
associated with the rapid and random movement of electrons within a conductor due to change in temperature
thermal noise
91
recovering information from a carrier is known as
detection
92
radio signals are made up of
electric and magnetic fields
93
electromagnetic waves produced primarily by heat are called
infrared rays
94
What does BIOS mean
Basic input output system
95
What is FTTH means
Fiber to the home
96
Facebook, twitter, instagram and the like has web level of
2
97
Which of the following is NOT a non volatile memory
RAM
98
What is NOT a programming language
oracle
99
MS-DOS is a/an ___ software
system
問題一覧
1
The basic reason why a full wave rectifier has twice the efficiency of a half wave rectifier is that
It utilizes both half cycle of the input
2
Which stage of a DC power supply uses zener diode as the main component
Regulator
3
A live room one whose interior finishing is such that reverbation time of sound is
less than 1
4
which of the following logic circuits is the fastest
transistor-transistor-logic (TTL)
5
The gate voltage in a FET at which the drain current Id becomes zero is called
pinch off voltage
6
The main factor which differentiates a DE MOSFET from E-only MOSFET is the absence of:
electrons
7
what electrode in a junction transistor corresponds to the cathode in a vacuum tube?
emitter
8
If the power level of an amplifier reduces to one-half, the dB gain will fall by.
3 dB
9
Piezoelectricity principle is applied in one of the following
Thermometer
10
In 1885, he used a long wire as antenna and developed a practical radio system
Marconi
11
It refers to a device that merely boosts a signal and passes it on
Repeater
12
RJ45 is used for.
Data
13
What is the most common fiber of the cable
Multi mode step index
14
What is the function of a transducer
Energy conversion
15
How many doped regions does a typical bipolar Junction transistor (BJT) have?
Three
16
An amplifier with a feedback loop or path for energy to propagate from the output back to the input is.
Regenerative feedback
17
Is the depletion region in a junction died forms what part of capacitor
Dialectric
18
Increasing the reverse bias on a varactor diode will cause its capacitance
Increase
19
What is the SI unit of thermodynamic temperature
Kelvin
20
Relative dialectic strength of gases tend with increasing molecular weight
Upward
21
Which of the following is the usual geometric view factor for a black body
One
22
Loudness of sound proportional to the square of
Amplitude
23
What is the maximum frequency which the human ear can hear
20,000 hz
24
Electromagnetic waves are refracted when they
Pass into a medium of different dialectric constant
25
The emission of electrons from matter by electromagnetic radiation of certain energy is
Photoelectric effect
26
The ratio of electric flux density to electric field intensity is called _____ of the medium
Permitivity
27
Wave propagation in perfect dialectric occurs
Without attenuation
28
For a perfect match between transmission line and load, the value of reflection coefficient should be
zero
29
The electromagnetic and electrostatic fields radiated by an antenna are out of phase by
90°
30
The physical relationship of gaseous system is treated by _______ of gases in which their properties are related to P, V and T of system
Kinetic theory
31
What is the branch of physics that deals with the dynamic property of gases
Pneumatics
32
The particle inside the nucleus is called
Nucleons
33
What do you call the nucleus a specific isotope of an element
Nuclide
34
If 1 g of matter could be converted entirely to energy, what would be the value of the energy to produce in kWh?
25x10^6
35
When the distance between two charges is doubled, the force between them will be equal to
One fourth
36
Which of the following laws of electromagnetic theory is connected with the force experience by two loops of a wire carrying a current
Ampere
37
____ is a scaler quantity
Potential in electric field
38
Steepness of the traveling waves in transmission line is attenuated by _____ of the line
Resistance
39
The absorption of radio waves by the atmosphere depends on which of the following
Frequency
40
The polarization of dialectric materials results in
Creation of electric dipole
41
Polarization of an electromagnetic wave is
The direction of its electric field component with respect to ground
42
A plane electromagnetic wave travels in a dialectric medium of relative permitivity of 9. Relative to free space, what is the velocity of propagation in the dielectric?
Reduce by a factor of one third
43
In transmission line the ratio of reflected power to incident power is given by
r2
44
Fundamental purpose is the transfer information from one electronic place to another
Electronic communication system
45
A collection of one or more electronic devices or circuits that converts the original source information to a form more suitable for transmission over a particular transmission medium
Transmitter
46
The process of changing one or more properties of the analog carrier in proportion with the information signal
Modulation
47
A modulation technique where the information signal is analog and the amplitude of the carrier is varied proportional to the information signal
AM
48
A specific band of frequencies allocated to a particular service
Channel
49
Signals in the 3 GHz to 30 GHz range and include the majority of the frequencies used for microwave and satellite radio communication systems.
SHF
50
The difference between the highest and lowest frequencies contain in the information
Bandwidth
51
The _____ of a waveform consists of all the frequencies contain in the wave form and their respective amplitude plotted in the frequency domain
Frequency spectrum
52
Noise can be reduced by
Narrowing the bandwidth
53
The ____ occurs when oscillating mechanical stresses applied across a crystal lattice structure. Generated electrical oscillations in vice versa.
Piezoelectric effect
54
The first stage of the receiver of which primary functions are detecting, band limiting and amplifying the received RF signal
RF section
55
The process of combining transmission from more than one source and then transmitting them over a common facility such as metallic or optical fiber cable or a radio frequency
multiplexing
56
A form of amplitude modulation in which the carrier is transmitted at full power, but only one of the sidebands is transmitted
SSBFC ( Single side band full carrier)
57
Half-duplex, one to many radios communication with two way no dial tone
Two way mobile radio
58
The ratio of the peak modulating signal voltage to the peak carrier voltage is
Modulation index
59
The operation of a fiber-optic cable is based on the principle of
Reflection
60
The core of the fiber-optic cable is surrounded by
Cladding
61
The electromagnetic waves produced primarily by heat are called
Infrared rays
62
Another name for signals in the HF range is
Short waves
63
Which color has the shortest wavelength of light
Blue
64
Electronic communications was discovered in which century?
19th
65
If the amplitude of the modulating signal applied to a phase modulator is constant, the output signal will be
carrier frequency
66
The TV signal uses which type of modulation for picture and sound respectively?
AM, FM
67
Random interference to transmitted signals is called
noise
68
The communication medium causes the signal to be
attenuated
69
Distortion of the modulating signal produces harmonics which cause an increase in the signal
bandwidth
70
The process of translating a signal with or without modulation to a higher or lower frequency for processing is called
Frequency conversion
71
How many pins comprise the RS232C
25
72
In a radio receiver, noise is generally developed at
RF Stage
73
It is the high frequency sound that cannot be heard by human ear.
ultrasonic
74
the number of frames per second in the Philippine television system is
30
75
What is the light source typically used in multimode optical fiber
LED
76
which of the following is a unit of information
dit
77
the most accurate type of test equipment used for measuring high power is the
bolometer
78
GSM has a fixed bit rate of
270 Kbps
79
bluetooth operates in what frequency
2.5 GHz
80
Simultaneous two-way communicatipns is called
full duplex
81
A display of signal amplitude versus frequency is called
frequency domain
82
Are signals in the 0.3 THz to 300 THz range and are not generally referred to as radio waves. Used in heat seeking guidance systems, electronic photography, and astoronomy
infrared
83
a signal that repeats at a uniform rate
periodic wave
84
It is a solid transparent fiber of flass or polymer that carries an optical signal
fiber optic
85
Are voltage or current that change in discrete steps or levels
digital signal
86
A modem converts
Both analog signals to digital and digital signals to analog signals
87
Any undesirable electrical energy that falls within the pass band of the signal
Electrical noise
88
Overmodulation results in
distortion
89
Demodulation is done in
radio receiver
90
associated with the rapid and random movement of electrons within a conductor due to change in temperature
thermal noise
91
recovering information from a carrier is known as
detection
92
radio signals are made up of
electric and magnetic fields
93
electromagnetic waves produced primarily by heat are called
infrared rays
94
What does BIOS mean
Basic input output system
95
What is FTTH means
Fiber to the home
96
Facebook, twitter, instagram and the like has web level of
2
97
Which of the following is NOT a non volatile memory
RAM
98
What is NOT a programming language
oracle
99
MS-DOS is a/an ___ software
system