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```NLC #3
+5 volts and ground
What voltage level exists in the 7400-serise of 1C chips?
0 and a logic 1 state
The majority of simple electronics circuits are based upon a logic...
0000 to 9999
A four decade counter can count from...
1, 0, 1 and 0
If the two inputs to a 2-input AND, NAND, OR, and NOR gate are both at logic 1, the outputs from the four gates are...
1.25
Assume that a length of wire having a resistance of 20 ohms is cut into four equal lengths. The four resistors then are connected
in parallel with each other and their resistance measured. The resistance, in ohms, will be...
1.25
A galvanometer has a resistance of 50 ohms and requires 0.05 amperes for full scale. The voltage required for half-scale
deflection is...
1 second
When R=I megohm and C=I microfarad, the RC time constant has a value of...
2.56
The current in a coil having an inductance of 32 millihenries increases in magnitude from 2 to 6 amperes in 0.05 second. The
voltage of self-induction will equal..
4
Two 50 watt, 120 volt heaters are connected in parallel to a 120 volt DC line. The power consumption is now X times as great as
it would be if they were connected in series. Assuming no change in resistance, X will be...
5
A storage cell is connected in series with a resistance of 0.3 ohms. If the resistance of the cell is 0.2 ohms and its EMF is 2.5 volts,
the current, expressed in amperes, in the circuit is...
5
A wire 50 feet long has a resistance of 10 ohm. The resistance of 25 feet of this wire is ___ ohms.
6
Two electrical condensers have capacitances of 9 and 18 microfarads, respectively, are connected in series. The capacitance, in
microfarads, of the two connected together will be...
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6
Three resistors, each of 12 ohms, connected in parallel with each other, are connected in series to a resistor of 6 ohms and to a
60 volt source. The current, in amperes, through the 6 ohms resistor will be...
10, 10
Of the following, the STRONGEST electromagnet is one having ____ amperes and ____ turns.
15
Eight Christmas tree lamps are connected in series on a 120 volt circuit. The voltage across each lamp is...
15
Four resistors of 60 ohms each are connected in parallel. Their combined resistance, in ohms, is...
17.5
A battery has an open circuit voltage of 20 volts and an internal resistance of 0.25 ohm. When it delivers a current of 10 amperes,
the terminal voltage will be...
30
Resistors of 5, 10, 15, and 30 ohms are connected in series to a battery. The GREATEST voltage drop will be across the resistor of
____ ohms.
115
A shunt motor having an armature whose resistance is 0.5 ohm is attached to a 120 volt supply. The armature current at full
speed is 10 amperes. The back EMF, in volts, will be...
141
A voltmeter showed a reading, when connected to a circuit carrying a sinusoidal alternating current, of 100 volts (RMS value).
The MAXIMUM instantaneous voltage was...
400
The combined resistance, in ohms, of four 100-ohm resistors connected in series is...
400
The MOST economical 0.1 mfd condenser to be used, without danger of shorting, on a 250 volt AC line is one whose DC working
voltage is rated at...
Only \$35.99/year
The 7490 is a decade counter, whereas the 7493 is a binary counter
What is the difference between a 7490 and a 7493 counter?
The current in an alternating current circuit is equal to the voltage multiplied by the...
All of the above
The term "to enable" a gate is the opposite of which of the following terms? (To close a gate; To disable a gate; To block a gate)
AND gate
For which type of gate is the following definition CORRECT? A binary circuit with two or more inputs and single output, in which
the output is a logic 1 only when all inputs are logic 1, and the output is logic 0 if any one of the inputs is logic 0.
attract each other
Two adjacent turns in a helical coil through which a constant current is passing through will...
both capacitative and inductive reactance
As the frequency of an alternating EMF ni a given circuit increases, the current in the circuit at first increases, then decreases.
The circuit contains...
can be transmitted more economically
One great advantage of AC over DC is that AC...
capacitance has been increased
A variable electrical condenser of the type used in radio sets is completely immersed in oil whose dielectric strength is 3.5. As
compared to its former state, its...
charge
When several capacitors are connected in series and to a source of direct current, each capacitor must have the same...
charge a storage battery
Only direct-current electricity may be used to...
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charge storage batteries
Direct current is necessary in order to...
curve in a vertical plane
An electron stream sent horizontally through a magnetic field whose lines of force are horizontal and at right angles to the
electron stream will...
electrons
A flow of electricity in a copper wire consists of a movement of...
expands at the same rate as glass
The alloy used for lead-in wires of electric lamps is chosen PRINCIPALLY because it...
F/2
If the capacitance in an oscillator circuit of frequency F is increased fourfold, the frequency of the oscillator becomes...
four gates
The 7400, 7402, 7408, and 7432 IC chips each contain...
frequency
In speaking of 60-cycle alternating current, the term 60 cycle refers to...
frequency
In describing an alternating current, the term 60 cycles per second refers to the...
from a logic 0 to a logic 1 and back to logic 0
A clock pulse is a transition...
galvanometer
Very small electric currents are measured by a(n)...
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A gate is essentially a one-way device, whereas a switch is a two-way device.
A gate and a switch differ in which of the following ways?
higher current
The wire in the primary of a step-up transformer is usually thicker than the wire in the secondary because the primary has the...
highest wattage
In a parallel circuit, the device with the LOWEST resistance has the...
high; series
A voltmeter is a galvanometer that has its movable coil connected with a _____ resistance in _____
Inverted input date
A gating input of logic 0 to a 2-input NOR gate will allow what type of digital information to appear at the output of the gate?
is easily magnetized and demagnetized
The core of an electromagnet is made of soft iron because soft iron...
logic 1 and logic 0
If the two inputs to a 2-input AND gate and a 2-input NOR gate are left unconnected, the outputs from these two gates are,
respectively...
logic 1, logic 0, logic 0, logic 1
In the truth tables for a 2-input AND, NAND, OR, and NOR gate, the unique output state is, respectively...
Logic 1 state
A gating input logic 0 to a 2-input NAND gate will allow what type of digital information to appear at the output of the gate?
makes sure that the output from the switch can be controlled to produce a single clock pulse at a time
When one debounces a SPDT switch, he...
monostable multivibrator
The 74121-IC chip is a...
moved back by the spring
The armature in an electric doorbell moves away from the magnet because it is...
NAND
When one inverts the output from an AND gate, he converts it into a(n) ____ gate.
NAND
The 7400, 7420, 7430 IC chips are all ____ gates.
negative trailing
In a positive clock pulse, the transition from logic 1 to logic 0 occurs on the ____ edge
not operate
A condenser is connected in series with a 25-watt lamp to a 120-volt DC source. The lamp will...
Peltier
When a current is made to flow in a circuit consisting of two unlike metals, heat is absorbed at one of the junctions and given off
at the other junction. This phenomenon is known as the ____ effect.
reverses the direction of the current in the armature coils
A commutator on a direct-current motor...
the same as
The current in a fuse is ____ the current in the circuit it protects.
the same as in A
In circuit A, one ampere of AC flows for 1 hour and generates X calories. In circuit B, one ampere of DC flows for 1 hour. The heat
generated in circuit B is...
the same as the field current
In a series would DC electrical generator, the current in the line is...
store electricity
A condenser is used to...
transformer
All of the following devices can be operated from a steady direct current EXCEPT a...
transformer
Of the following (flatiron, heating coil, lamp, transformer), the device that should NOT be connected to a DC source is a...
transformer
Steady direct current cannot be used to operate a(n)...
Two
A common cathode display has the following inputs to its segments: C,F=0 and A,B,D,E,G=1 ; What dose the display indicate?
two, three, four, eight
The 7400, 7420, and 7430 IC chips have gates that have, respectively, the following numbers of inputs...
voltage between cathode and anode
The penetrating power of the x-rays produced by a Coolidge x-ray tube can be increased by increasing the..
volts
The potential difference in a circuit is measured in...
zero
In an AC circuit in which the current and voltage are out of phase by 90 deg, an ammeter reads 2 and a voltmeter reads 120. The
power expended by this circuit, in watts, equals...
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