問題一覧
1
If bandwidth increases, the
Q decreases
2
the dc output of a bridge type circuit is__ that of equivalent center tapped circuit.
more than
3
Which of the following robot drive mechanism is the cheapest to buy but has a limited payload?
pneumatic
4
The output of an OR gate will be low if
all inputs are LOW
5
If a 175-V dc source were connected in series with the utility mains from a standard wall outlet, the result would be
fluctuating dc
6
In constructing transformers, the primary and secondary windings should have
tight magnetic coupling
7
If a sine wave voltage varies from 0-200 V, how much is its instant voltage at 90 degrees?
200 V
8
What is the typical slew rate of Fairchild 741 op-amp?
0.5 V/us
9
Small microcomputer used as a dedicated controller for a machine, a piece of equipment, or a process.
Microcontroller
10
Where do you classify cobalt as material?
Ferromagnetic
11
If the base-emitter junction is open, the collector voltage is
Vcc
12
The absolute maximum rating for op-amps interval power dissipation is
500mW
13
The power dissipated in the core due to hysteresis and eddy current losses
iron loss
14
Which of the following is not an internal digital IC fault?
poor solder connections
15
A diode limiter circuit
can cause objectionable signal distortion
16
An elementary generator consists of a single coil rotating in a magnetic field. Why is no voltage induced in the coil as it passes through the neutral plane?
Flux lines are not being cut
17
A manufacturer quotes in his specifications that a silicon diode conducts 50 mA at 1 V. Determines its bulk resistance.
6 ohms
18
A radio equipment will be used to 70% at 50 amperes rating fo 5 hours, how much capacity of dry battery is needed?
175
19
Type of feedback employed in oscillators
positive
20
A digital circuit that oscillates between two unstable output states.
astable multivibrator
21
Capacitors are used to store data in
none of the above
22
The input resistance of a common-base amplifier is
very low
23
What is the normal resting state of the SET and CLEAR inputs in a NAND gate latch?
SET=1, CLEAR=1
24
Voltage that is present at the output of an operational amplifier with its two inputs grounded.
output offset voltage
25
Type of waveform generated by the sweep generator of the CRT
sawtooth
26
What are the primary methods of controlling electrical power?
all of the above
27
Class of programmable logic devices wherein its AND array is programmable while its OR array is hard wired.
PAL
28
Flux linkage equals
flux times number of turns
29
The device used to use for rectifying a weak ac signal is a
Back Diode
30
How many NAND-gates are required to form an OR-gate?
3
31
What gain is significant when an op-amp is used as a voltage comparator?
open-loop gain
32
Process of repairing the ruptured crystal structure caused by ion implantation by heating.
annealing
33
Suppose a purely resistive impedance of 75 Ω must be matched to a purely resistive impedance of 300 Ω. A quarter-wave section would need to have
Zo=150 Ω
34
How many cells would a 16 word x 6 bit memory contain?
96
35
Find the half-power bandwidth of a parallel resonant circuit which has a resonant frequency of 8.1 MHz and Q of 150.
54 kHz
36
The purpose of the I layer in a PIN diode is to
minimize the diode capacitance
37
The typical saturation flux density for most magnetic materials.
2 Wb/m2
38
_____ is a measure of consistency of measurements.
precision
39
A digital computer used for the automation of industrial processes, such as control of machinery or factory assembly lines
PLC
40
A JFET always operates with
the gate-to-source pn junction reverse-biased
41
If Ic is 50 times greater than IB, then βDC is
50
42
What is the ripple frequency of a half-wave rectifier with an input line frequency of 60 Hz?
60 Hz
43
Which of the following amplifiers is considered linear?
either class A or B
44
Electrical classification of materials having 8 electrons.
insulator
45
A full 360 deg sine wave signal is applied to an unknown class of amplifier. If the output delivers only a pulse of less than 180 deg, what class does this amplifier belongs?
class C
46
Which of the following is not a general characteristic of an ac wave?
the electrons always flow in the same direction
47
A summing amplifier can have
Two or more input signals
48
In an NPN circuit, the collector
is positive with respect to the emitter
49
The bandwidth of a multistage amplifier is ___ that of a single stage amplifier.
less than
50
A device used to mechanically measure the output power of a motor
dynamometer
51
How many major lobes are produced by a paraboloid reflector?
one
52
The main problem with a bar-graph meter is that:
it can’t give a very precise reading
53
What is the maximum efficiency of a full-wave center-tapped rectifier?
81.2%
54
Which of the following is false, concerning air cores versus ferromagnetic cores?
air concentrates the magnetic lines of flux
55
Which statement is wrong regarding μA741 when its supply voltage is increased?
large variation in the input offset voltage
56
If a power supplies 30 V with no load and 20V under full load, what is the percentage regulation?If a power supplies 30 V with no load and 20V under full load, what is the percentage regulation?
50%
57
Which type of the following oscillator types uses transformer coupling to feed back a portion of the signal voltage. It is sometimes called a “tickler” coil.
Armstrong circuit
58
A pulsating dc applied to power amplifiers causes
hum in the circuit
59
In a linear op-amp circuit, the
Op-amp does not go into saturation
60
Situation when a circuit’s output level for a given set of input conditions can be assigned as either a 1 or 0.
don’t care
61
The regulator with the highest efficiency is the
switching regulator
62
When a closed-loop system is used to maintain physical position it is referred to as
servo system
63
An integrated circuit for both astable and monostable applications
555 timer
64
Result obtained when a 1 is added to the least significant bit position of a binary number in the 1’s-complement form
2’s complement
65
Low sensitive DC voltmeter provides inaccurate result when measuring ____ circuits.
high resistance
66
Simple current limiting produces too much heat in
Pass transistor
67
When an armature opens in dc motor, it may cause
intermittent sparking
68
.Suppose you have an unlimited supply of 1-W, 1000-Ω resistors, and you need a 500-Ω resistance rated at 7 W or more. This can be done by assembling
four sets of two resistors in series, and connecting these four sets in parallel
69
A significant advantage, in some situations, of a toroidal coil over a solenoid is the fact that
the magnetic flux in a toroid is practically all within the core
70
The input offset current is usually
less than the input bias current
71
Combination of ac motor, dc generator, and exciter to provide adjustable voltage dc power to a dc motor.
ward-leonard system
72
The ideal internal resistance of an emitter should be
zero
73
A frequency synthesizer has
exceptional stability
74
The approximation with a maximally flat passband is
Inverse chebyshev
75
Electron flow assumes charges flow from
negative to positive
76
The closed-loop voltage gain of an inverting amplifier equals
The feedback resistance divided by the input impedance
77
A bubble memory is best suited for:
a large computer
78
The operating frequency of a Wien-bridge oscillator is given by ___.
1/2piRC
79
In an LC oscillator, if the value of L is increased four times, then frequency of oscillations is ____.
decreased two times
80
This type of electrical machine is used for varying the input voltage into a higher or lower potential without changing the power transferred.
transformer
81
Amplifier of low-level signals that provides an output that is an accurate multiple of the difference between two input signals
instrumentation amplifiers
82
Which of the following is not a characteristic of CMOS chips?
ability to handle extremely high power
83
How are the networks able to transform one impedance to another?
Resistance in the networks substitute for the resistances in the load.
84
Power source that converts desired electricity to the other.
motor set
85
It is a robot structure wherein the body can pivot vertically and horizontally and that arms move radially
polar structure
86
How do you determine if diode is effective?
diode resistance is either very high or very low in either direction
87
The energy of an oscillator can be sourced by
capacitance of inductive coupling from the tuned circuit
88
Air works well as a dielectric mainly because it
has low loss
89
An AC bridge that measures inductance in terms of resistance and capacitance.
Owen’s bridge
90
A monopulse receiver has how many separate channels?
three
91
A meter when ___ damped will become insensitive to small signals.
overdamped
92
In a linear regulator, the control transistor is conducting
all of the time
93
Each stage of a four-stage amplifier has a voltage gain of 15. The overall voltage gain is
50,625
94
With respect to memory, which of the following terms means that the data contents vanish if power is removed from a chip?
volatility
95
What is the purpose of the emitter capacitor?
to avoid drop in gain
96
The number of digits used by a number system.
radix
97
A Schmitt trigger is used to provide
A short duration pulse
98
One of the following items below is not one of the main components of an alternating current power supply.
Rectifier
99
What are the two basic categories of industrial robots?
pick and place manipulator and intelligent robot
100
What direction is the magnetic field about a conductor when current is flowing?
in a direction determined by the left hand rule