Electronics

Question 1

you have a 47uH inductor what capacitor is needed to resonate that inductor to 4.5MHz

Answer 1

266pf

Question 2

what is a snubber used for

Answer 2

surge suppression

Question 3

which of the following semiconductors most susceptible to electrical noise and ESD
A) CMOS
B) DTL
C) TTL
D) FET

Answer 3

DTL
Digital Transistor Logic

Question 4

a transformer has a secondary voltage of 120 volts. the primary winding has 1800 turns and the secondary has 90 turns. whats the primary voltage

Answer 4

2400 volts

Question 5

three 0.033microfarad capacitors are connected in series across a 1000HZ signal generator what is the total capacitance as seen by the generator
A) 0.011 micro farad
B) 0.033 micro farad
C) 0.099 micro farad
D) 0.00133 micro farad

Answer 5

0.011 microfarad

1/ ((1-C1)+(1/C2)+(1/C3)) or if equal capacitance / number of capacitors

Question 6

what is a wheatstone bridge used to measure

Answer 6

unknown resistance

Question 7

what is used to boost a digital signal
A) repeater
B) booster
C) amplifier
D) multiplier

Answer 7

repeater

Question 8

current is series circuit ______after passing through each resisitor in the circuit.

Answer 8

unchanged

Question 9

definition of a series circuit

Answer 9

only has 1 path for current flow

Question 10

current state of a decade counter is 1000, after 3 clock pulses the state becomes

Answer 10

0001

Question 11

ripple frequency of full wave rectifier should be

Answer 11

120 Hz

Question 12

input stage to an integrated circuit operational amp is

Answer 12

differential amp

Question 13

impedance of a series LC circuit is

Answer 13

minimum at resonance

Question 14

where would you find a snubber

Answer 14

a SCR circuit with an inductive load

Question 15

how many inputs and outputs are possible with a differential amp
A) two inputs and one output
B) two input and two output
C)
D)

Answer 15

2 inputs and 1 output

Question 16

196
in the figure below which of the following is not true

Answer 16

If pins 1 and 4 are low the output is high

Question 17

203
in figure below assuming pin 4 is pulled low after a pulse occurs on pin 14 then 6 clock pulses on pin 5 what are the outputs of Q-0 thru Q-3 respectfully
A) 11
B)1001
C) 0110
D) 1010

Answer 17

0110

Question 18

205
In the figure below with pins 15 and 1 high, 10 and 9 low, pin 11 is pulsed with pin 4 pulled low, how many clock pulses are needed on pin 5 for pin 7 to go high
A) 4
B) 7
C) 5
D) 6

Answer 18

5

Question 19

200
figure below is an up/down binary counter after a pulse occurs on pin 14, how many clock pulses need to occur on pin 5 in order for the carry out function on pin 12 to go low. assume pin 4 is pulled low
A) 15
B) 8
C) 7
D) 16

Answer 19

15

Question 20

195
what is the function of d-type flip flop in the figure below.

Answer 20

Clock divider

Question 21

initial content of a 4 bit bi-directional shift register is 0011. serial input contains 1100 after applying 2 clock pulses when control line is set shift-left mode and then 2 clock pulses when the control line is set to shift-rt mode. the serial output contains.
A) 11
B) 1100
C) 1111
D) 0

Answer 21

11

Question 22

true or false serial in-serial out shift register can be used as a time delay device and the number of flip-flops used can alter the amount of the delay

Answer 22

true

Question 23

194
in the figure below which of the following is true

Answer 23

If either input is high the output will be low

Question 24

what can be used to match high impedance to low impedance

Answer 24

transformer, pad emitter follower (or voltage common collector)

Question 25

output of an 8 -bit serial in serial out shift register is connected back to it input. assume the initial content of the shift register is 11000011 after 4 clock pulses, the content becomes A) 111100 B) 1111 C) 11110000 D) 11000011

Answer 25

111100

Question 26

202 Figure below is what time of device A) 1 0f 8 decoder B) binary counter C) octal latch D) 8 bit shift register

Answer 26

1 of 8 decoder

Question 27

199 components in the figure below make up what kind of circuit A) schmitt trigger B) two input NOR gate C) free running oscillator D) Flip Flop

Answer 27

Flip flop

Question 28

177 Figure below is an Octal Bus transceiver. What is its most common application? A) address decoder B) data latch C) two way data communication between data busses D) comparator

Answer 28

two way data communications between busses

Question 29

figure below, pin1 is low, 2 and 3 are high, 4 and 5 are low and 6 is high. What output pin will be low A) 9 B) 7 C) 10 D) none

Answer 29

9

Question 30

primary voltage of a transformer is 480 volts and the secondary is 240 volts. the turn ration of this transformer is_______?

Answer 30

2 : 1

Question 31

197 the figure below is an octal latch. Which of the following is true? A) contents of the latch can only be changed when a clock pulse (CP) occurs B) the data on the outputs can only be presented when the signal OE is high C) the contents of the latch cannot be changed if the signal OE is high D) the data on the output will be the inverse of the data that was input.

Answer 31

contents of the latch can only be changed when a clock pulse (CP) occurs

Question 32

198 figure below , what signal or signals determine if transfer is from A to B bus or B to A bus. A) A-0 thru A-7 B) E C) B-0 thru B-7 D) DR

Answer 32

DR

Question 33

201 device is the figure below A) serial in serial out shift register B) parallel shift register C) serial in parallel out shift register D) binary counter

Answer 33

serial in parallel out shift register

Question 34

204 figure below the intitial contents of Q-0 through Q-7 are 11000011. The input contains a data stream of 10101110. after 4 more clock pulses the output of Q-0 through Q-7 becomes. A) 11000011 B) 11101100 C) 111010 D) 1010011

Answer 34

11101100

Question 35

Disadvantage of Darlington amplifier in a power circuit is A) relatively high internal current B) poor transient response C) low beta D) poor low freq response

Answer 35

relatively high internal current

Question 36

Main disadvantage to an asynchronous counter is_______? A) propagation delay on the clock pulse as it "ripples through" the flip flop stages B) propagation delay on the Q output as it passes to the input of the following stages C) the number of flip flops D) all answers are correct

Answer 36

all answers are correct

Question 37

Which of the following is a characteristic of an SCR? A) it has a fast turn on when a pulse is delivered to the gate and the anode is positive, with response to the cathode B) once it starts conducting it can not be shut off by the gate voltage input C) it conducts only in one direction D) all answers are correct

Answer 37

all answers are correct

Question 38

Two different, pure sine wave frequencies are delivered to a linear amplifier at the same time. An oscilloscope display shows that more that two frequencies are at the output. the problem is A) anti-resonance B) RF/ noise gain C) inter-modulation distortion D) ringing

Answer 38

RF/ Noise gain

Question 39

What is the standard connector type for DMX-512

Answer 39

5 pin XLR

Question 40

Advantage of saw-tooth testing over square-wave testing is ?> A) shows clipping B) easier to read C) costs less D) easier to setup

Answer 40

shows clipping