FE ELECTRICAL – SECOND SIMULATION

#1. [Power Systems] Ideal transformer with turns ratio Np:Ns=4:1 feeds load 22 Ω on secondary. Reflected primary impedance is:

1.375 Ω

1.513 Ω

1.622 Ω

1.127 Ω

#2. [Signal Processing] For FIR filter y[n]=x[n]+0.5x[n-1]+0.25x[n-2], with x[0]=5, x[1]=5, x[2]=2, find y[2].

6.785

5.75

4.312

4.715

#3. [Engineering Economics] A retrofit costs $184,961 now and saves $32,417/year for 6 years. At MARR = 12%, what is NPV?

-51681.5 USD

-38761.1 USD

-56849.7 USD

-64601.9 USD

#4. [Engineering Economics] Compute capital recovery (EUAC) for P=$170,798, S=$45,200, n=10 years, i=8%.

27917.3 USD/yr

22333.8 USD/yr

20100.4 USD/yr

24567.2 USD/yr

#5. [Computer Systems] Cache hit rate=0.90, hit time=2.88 ns, miss penalty=63.7 ns. AMAT is:

7.48 ns

10.034 ns

9.122 ns

11.402 ns

#6. [Power Systems] A balanced 3-phase load consumes 323 kW at 212 V line-line and pf=0.91 lagging. Line current is:

1136.1 A

1203.5 A

1059.1 A

962.8 A

#7. [Digital Systems] A static-1 hazard in combinational logic is typically mitigated by:

Adding consensus terms to cover adjacent minterms

Reducing supply voltage to slow transitions

Clocking the combinational block

Replacing all AND gates with XOR gates

#8. [Ethics and Professional Practice] You discover a grounding omission that violates code, but correcting it will delay commissioning and trigger penalties. What is the MOST ethical action?

Let the contractor decide whether to disclose the issue

Document the hazard, notify responsible authority immediately, and halt affected work until corrected

Proceed temporarily and note it in final report

Inform only your manager verbally and continue work

#9. [Circuit Analysis] An AC source of 113 Vrms drives impedance Z = 23 + j7 Ω. RMS current magnitude is:

4.23 A

3.854 A

4.7 A

5.546 A

#10. [Power Systems] A 4-pole induction motor on 60 Hz runs at 1773 rpm. Rotor current frequency is closest to:

1.062 Hz

1.125 Hz

0.675 Hz

0.9 Hz

#11. [Electronics] In instrumentation design, which action most effectively reduces common-mode interference in low-level sensor measurements?

Use differential signaling with high CMRR front-end and proper shield grounding

Place the sensor farther from the instrumentation amplifier

Use single-ended wiring and average more samples

Increase ADC sampling rate without changing front-end topology

#12. [Electronics] A BJT in active mode has β=159 and base current 94.6 µA. Collector current is closest to:

13.532 mA

15.035 mA

17.742 mA

11.277 mA

#13. [Control Systems] For unity-feedback type-0 system with open-loop DC gain K=7, unit-step steady-state error is:

0.156

0.113

0.125

0.102

#14. [Circuit Analysis] A Thevenin source Vth=26 V with Rth=10 Ω feeds RL=6 Ω. Load current is:

1.463 A

2.031 A

1.788 A

1.625 A

#15. [Mathematics] For first-order decay dy/dt = -2y with y(0)=1, find y(0.96 s).

0.147

0.132

0.161

0.12

#16. [Control Systems] For unity-feedback type-0 system with open-loop DC gain K=12, unit-step steady-state error is:

0.058

0.077

0.096

0.069

#17. [Computer Networks] For IPv4 subnet /25, how many usable host addresses are available?

103.3

94.5

126

157.5

#18. [Linear Systems] For low-pass H(jω)=1/(1+jωτ) with τ=0.208 s, find |H(jω)| at ω=2 rad/s.

0.831

1.154

1.016

0.923

#19. [Circuit Analysis] A current source 10 A feeds two parallel resistors 4 Ω and 10 Ω. Node voltage across the pair is:

28.571 V

25.714 V

35.714 V

23.429 V

#20. [Linear Systems] A transfer function has poles at s=-4.67 and s=-6.67. Dominant time constant is closest to:

0.161 s

0.214 s

0.175 s

0.193 s

#21. [Communications] For M-ary signaling with M=8 and bit rate 250 kb/s, symbol rate is:

75 ksym/s

68.333 ksym/s

83.333 ksym/s

104.2 ksym/s

#22. [Digital Systems] Minimum number of flip-flops required for a MOD-9 synchronous counter is:

3.6

4.72

4.4

4

#23. [Circuit Analysis] In an RL step response with V=20 V, R=11 Ω, L=0.344 H, find i(t) at t=0.031 s.

1.151 A

1.358 A

0.944 A

1.266 A

#24. [Signal Processing] A first-order analog low-pass has cutoff 800 Hz. At cutoff frequency, output magnitude relative to passband is:

0 dB (unity)

-3 dB (approximately 0.707 of passband amplitude)

-6 dB (half amplitude)

+3 dB (resonant peak)

#25. [Software Engineering] Which data structure gives O(1) average-time lookup for symbol tables while allowing occasional rehash operations?

Singly linked list

Binary heap

Hash table

Unbalanced binary search tree

#26. [Computer Networks] A router has routes 10.2.0.0/16, 10.2.32.0/19, and 10.2.32.128/25. Packet to 10.2.32.200 follows which route?

10.2.32.0/19

10.2.0.0/16

Default route only

10.2.32.128/25 (longest-prefix match)

#27. [Ethics and Professional Practice] A former employer’s proprietary control code could shorten your current project by weeks. What is the proper action?

Do not reuse protected code; obtain permission or develop an original implementation

Use it temporarily and remove before delivery

Reuse code if variable names are changed

Reuse only non-commented sections

#28. [Electromagnetics] For a long straight conductor carrying 66 A, magnetic flux density at radius 0.109 m is:

1.33e-04 T

1.21e-04 T

1.43e-04 T

9.08e-05 T

#29. [Electromagnetics] Transmission line has Z0=63 Ω and load ZL=60 Ω (real). Reflection coefficient Γ at load is:

-0.02

-0.03

-0.024

-0.029

#30. [Electromagnetics] For a lossless medium with εr=1 and μr=1.5, intrinsic impedance η is:

415.6 Ω

378.6 Ω

346.3 Ω

461.7 Ω

#31. [Control Systems] For characteristic equation s^2 + 4s + 4=0, which range of k ensures stability?

k > 0

k < 0

k = 0 only

k > 16 only

#32. [Electronics] A BJT in active mode has β=153 and base current 71.4 µA. Collector current is closest to:

9.835 mA

10.928 mA

12.021 mA

8.196 mA

#33. [Electromagnetics] If electric field changes at dE/dt=7.95e+06 V/m·s in a dielectric with permittivity 8.85e-12 F/m, displacement current density Jd is:

7.75e-05 A/m²

5.77e-05 A/m²

7.04e-05 A/m²

8.31e-05 A/m²

#34. [Power Systems] Transformer no-load secondary voltage is 128 V and full-load is 116 V. Voltage regulation is:

12.207 %

12.931 %

9.31 %

10.345 %

#35. [Mathematics] For f(t) = t^3 – t^2 + 5t, evaluate d f/dt at t = 3.

26

28.6

19.5

21.32

#36. [Computer Systems] In interrupt-driven embedded systems, which design choice best reduces worst-case interrupt latency?

Disable caches during interrupt handling

Keep critical sections short and prioritize ISRs with bounded execution

Use deeply nested interrupts without masking policy

Move all ISR work into polling loops

#37. [Electronics] Half-wave rectifier with peak input 15 V, diode drop 0.7 V, RL=415 Ω. Approximate average load current:

9.871 mA

8.994 mA

10.968 mA

8.226 mA

#38. [Control Systems] A standard 2nd-order closed-loop system has damping ratio ζ=0.46. Percent overshoot is closest to:

16.325 %

14.931 %

21.899 %

19.908 %

#39. [Linear Systems] For system y” + 4y’ + 1y = u(t), which statement about stability is true?

Stable because all coefficients are positive and roots have negative real parts

Marginally stable because second-order systems always oscillate

Unstable unless b > a^2

Unstable because input is a step function

#40. [Computer Systems] Cache hit rate=0.94, hit time=1.80 ns, miss penalty=40.4 ns. AMAT is:

5.385 ns

4.308 ns

3.231 ns

3.877 ns

#41. [Control Systems] A loop has crossover ωc=20.0 rad/s and phase margin 61.1°. Which interpretation is best?

System is marginally stable only if gain margin is exactly 0 dB

System is unstable because crossover frequency is finite

Positive phase margin indicates closed-loop stability with moderate robustness

Phase margin does not relate to time-domain overshoot

#42. [Digital Systems] Pipeline stage has tCQ=1.83 ns, combinational delay=4.71 ns, setup=1.14 ns. Max clock frequency is:

117.4 MHz

97.831 MHz

107.0 MHz

130.4 MHz

#43. [Electronics] Ideal inverting op-amp with Rin=7 kΩ, Rf=79 kΩ, Vin=0.700 V. Output is:

-7.904 V

-6.481 V

-9.88 V

-8.695 V

#44. [Properties of Electrical Materials] Estimate skin depth δ for a conductor with σ=4.18e+07 S/m, μr=50, at f=1000 Hz.

3.13e-04 m

3.48e-04 m

4.35e-04 m

2.61e-04 m

#45. [Mathematics] An engineer linearizes a calibration model and obtains equations 3x + 2y = 16 and x + 3y = 9. What is x?

7.857

5.657

6.286

7.417

#46. [Control Systems] Increasing integral gain Ki in a PID controller most directly tends to:

Reduce sensor noise sensitivity at high frequency

Eliminate need for derivative action in all plants

Increase phase margin and always improve damping

Reduce steady-state error while risking increased overshoot/oscillation

#47. [Mathematics] In a fully connected sensor graph with 5 nodes, how many unique undirected links exist?

10

11.8

12.5

11

#48. [Mathematics] A phasor is V = 5 + j8. What is |V|?

10.377

9.434

11.792

7.736

#49. [Control Systems] A standard 2nd-order closed-loop system has damping ratio ζ=0.70. Percent overshoot is closest to:

5.552 %

3.642 %

4.441 %

4.886 %

#50. [Computer Systems] Compared with programmed I/O, DMA primarily improves system performance by:

Eliminating the need for interrupts

Increasing ALU clock frequency directly

Making memory accesses deterministic under all loads

Transferring bulk data with minimal CPU intervention

#51. [Signal Processing] For y[n]=0.57y[n-1]+(-0.35)y[n-2]+x[n], which is correct?

BIBO stable (dominant poles inside unit circle)

Cannot determine stability without x[n]

Always stable because coefficients are finite

Always unstable for second-order IIR filters

#52. [Circuit Analysis] A branch dissipates 396 W with RMS current 1.46 A. Equivalent resistance is:

139.6 Ω

186.1 Ω

219.6 Ω

152.6 Ω

#53. [Properties of Electrical Materials] A package heat spreader has k=189.1 W/m·K, area=1.91e-04 m², thickness=0.024 m, and ΔT=25 K. Conduction heat rate is:

40.86 W

33.431 W

37.146 W

27.859 W

#54. [Properties of Electrical Materials] A parallel-plate capacitor originally has air dielectric and unchanged geometry. If replaced by a dielectric with relative permittivity εr, capacitance changes by what factor?

0.455

4.84

1.483

2.2

#55. [Linear Systems] For a 2nd-order system with damping ratio ζ=0.71 and ωn=12.67 rad/s, estimate 2% settling time.

0.444 s

0.333 s

0.399 s

0.524 s

#56. [Circuit Analysis] Node A is connected to 21 V through 7 Ω and to 18 V through 7 Ω. What is node voltage Va (no load)?

14.625 V

19.5 V

21.45 V

17.55 V

#57. [Digital Systems] Which statement about asynchronous inputs to flip-flops is most accurate?

They eliminate race conditions by definition

They never affect MTBF in digital systems

They can induce metastability and require synchronization before use in synchronous logic

They are safe if setup time is met at the source

#58. [Communications] Using Shannon capacity C = B log2(1+SNR), with B=1.0 MHz and linear SNR=30, capacity is:

4.459 Mb/s

5.45 Mb/s

4.062 Mb/s

4.954 Mb/s

#59. [Power Systems] A balanced 3-phase load consumes 176 kW at 369 V line-line and pf=0.82 lagging. Line current is:

334.9 A

395.1 A

251.1 A

368.3 A

#60. [Probability and Statistics] 25% of failures are due to power-stage faults. A thermal alarm appears with conditional probabilities P(A|power) and P(A|non-power) as given. What is P(power | alarm)?

0.629

0.571

0.429

0.514

#61. [Software Engineering] A loop nest runs: for i=1..n, for j=1..i. Time complexity is:

O(log n)

O(n^3)

O(n^2)

O(n)

#62. [Electromagnetics] For a lossless medium with εr=1 and μr=1, intrinsic impedance η is:

339.3 Ω

414.7 Ω

444.9 Ω

377 Ω

#63. [Computer Networks] Which security control BEST addresses lateral movement after initial endpoint compromise?

Network segmentation with least-privilege access and east-west monitoring

Increasing WAN bandwidth

Disabling all ICMP traffic globally

Using only perimeter firewalls without internal controls

#64. [Software Engineering] Worst-case comparisons for binary search on sorted array of size 256 are closest to:

9.44

8

7.2

6

#65. [Digital Systems] Minimum number of flip-flops required for a MOD-11 synchronous counter is:

4.72

3

4

3.6

#66. [Power Systems] At a 29 kV bus with Thevenin reactance 0.205 Ω (line-line basis), 3-phase bolted fault current is approximately:

96592.1 A

61393.3 A

73672.0 A

81857.7 A

#67. [Probability and Statistics] Assuming normal process variation with mean 119 and std dev 15, what is the 95th percentile?

143.7

107.8

179.6

158.0

#68. [Circuit Analysis] An AC source of 219 Vrms drives impedance Z = 11 + j17 Ω. RMS current magnitude is:

8.869 A

10.816 A

12.762 A

11.897 A

#69. [Digital Systems] Pipeline stage has tCQ=2.15 ns, combinational delay=7.43 ns, setup=1.91 ns. Max clock frequency is:

71.383 MHz

78.347 MHz

87.053 MHz

108.8 MHz

#70. [Linear Systems] For G(s)=1/(s+2), unit-step response final value is:

0.3

0.367

0.273

0.333

#71. [Mathematics] An engineer linearizes a calibration model and obtains equations 2x + 2y = 16 and x + 5y = 11. What is x?

9

10.62

6.75

11.25

#72. [Electronics] Using square-law saturation model Id=0.5k(VGS−VT)^2, find Id for k=0.0030 A/V², VGS=3.81 V, VT=1.54 V.

5.772 mA

7.696 mA

8.465 mA

6.311 mA

#73. [Ethics and Professional Practice] A vendor offers expensive gifts while a bid decision is pending. Which action best aligns with professional ethics?

Accept gifts if no explicit contract terms are changed

Accept gifts and disclose after award

Decline gifts and ensure procurement remains impartial and documented

Accept gifts under a personal relationship exemption

#74. [Signal Processing] A tone at 6300 Hz is sampled at fs=10000 Hz. Observed baseband alias frequency is:

4366 Hz

4625 Hz

3034 Hz

3700 Hz

#75. [Engineering Economics] For a test fixture: fixed cost $128,576, unit price $105, variable cost $36. Break-even quantity is closest to:

1863.4 units

1397.6 units

2049.8 units

1677.1 units

#76. [Computer Systems] By Amdahl’s law, fraction parallelizable p=0.52 with accelerator speedup 2.03. Overall speedup is:

1.494

1.358

1.698

1.019

#77. [Circuit Analysis] Node A is connected to 14 V through 2 Ω and to 11 V through 2 Ω. What is node voltage Va (no load)?

11.25 V

15.625 V

12.5 V

13.75 V

#78. [Electronics] Ideal inverting op-amp with Rin=13 kΩ, Rf=31 kΩ, Vin=0.610 V. Output is:

-1.717 V

-1.309 V

-1.193 V

-1.455 V

#79. [Mathematics] Compute the integral ∫_0^5 x^2 dx.

41.667

49.167

45.833

52.083

#80. [Electronics] An ideal 12-bit ADC with Vref=5.0 V measures Vin=1.250 V. Output code is closest to:

1278.8

1023

920.7

1207.1

#81. [Digital Systems] In unsigned 4-bit arithmetic, adding 0 and 4 sets carry-out flag to:

undefined

depends on signed interpretation

0

1

#82. [Computer Systems] A 32-bit, direct-mapped cache has 64 sets and 32-byte blocks. Tag bits per line are:

15.75

26.25

18.9

21

#83. [Communications] For an AM wave, envelope Vmax=4.24 and Vmin=1.50. Modulation index m is:

0.479

0.527

0.359

0.565

#84. [Circuit Analysis] A branch dissipates 359 W with RMS current 6.01 A. Equivalent resistance is:

7.461 Ω

9.949 Ω

10.943 Ω

12.436 Ω

#85. [Power Systems] Transformer no-load secondary voltage is 121 V and full-load is 121 V. Voltage regulation is:

-0.258 %

-0.307 %

0 %

0.119 %

#86. [Ethics and Professional Practice] A client asks you to stamp a design prepared entirely by another engineer that you did not supervise. What should you do?

Seal it if the other engineer signs an email attestation

Seal only the pages that look correct on quick review

Seal it if the schedule is critical

Decline to seal until you have sufficient responsible charge and verification

#87. [Properties of Electrical Materials] A conductor has resistivity 1.99e-08 Ω·m at 20°C and temperature coefficient 0.0037/°C. Estimate resistivity at 100°C.

2.58e-08 Ω·m

2.24e-08 Ω·m

2.94e-08 Ω·m

1.88e-08 Ω·m

#88. [Digital Systems] Which expression is equivalent to Boolean function F = A’B + AB (sum of products)?

A’ + B’

B

A + B

A

#89. [Engineering Economics] Two design alternatives have scenario payoffs (high/medium/low demand): A=[140k,60k,-20k], B=[90k,70k,10k] with probabilities [0.2,0.5,0.3]. Best EMV is:

42000 USD

50400 USD

56000 USD

45920 USD

#90. [Signal Processing] A tone at 5500 Hz is sampled at fs=8000 Hz. Observed baseband alias frequency is:

3125 Hz

2750 Hz

2050 Hz

2500 Hz

#91. [Mathematics] In a fully connected sensor graph with 9 nodes, how many unique undirected links exist?

36

29.52

32.4

39.6

#92. [Probability and Statistics] A communication node retransmits X times with PMF P(X=0,1,2,3) = {0.10, 0.35, 0.40, 0.15}. What is E[X]?

2

1.6

1.888

1.2

#93. [Communications] A TDM PCM system multiplexes 35 channels, each sampled at 16000 Hz with 10 bits/sample. Aggregate data rate is:

6.608 Mb/s

4.592 Mb/s

5.6 Mb/s

5.04 Mb/s

#94. [Probability and Statistics] A lot has independent defect probability 0.02 per board. For 12 boards, what is P(at least 2 defect)?

0.017

0.029

0.027

0.023

#95. [Mathematics] Compute the integral ∫_0^6 x^2 dx.

72

84.96

64.8

90

#96. [Circuit Analysis] A current source 3 A feeds two parallel resistors 6 Ω and 11 Ω. Node voltage across the pair is:

10.482 V

11.647 V

12.812 V

14.559 V

#97. [Software Engineering] Which testing strategy is best for validating boundary behavior of ADC register parsing logic?

Code formatting checks as primary validation

Random testing only, without deterministic edge cases

Boundary value analysis with explicit min/max and off-by-one cases

Integration testing only after deployment

#98. [Signal Processing] For an ideal 14-bit ADC, quantization-limited SQNR is closest to:

107.6 dB

77.436 dB

94.644 dB

86.04 dB

#99. [Circuit Analysis] In an RL step response with V=26 V, R=40 Ω, L=0.242 H, find i(t) at t=0.023 s.

0.634 A

0.52 A

0.476 A

0.793 A

#100. [Power Systems] A component has reactance 0.168 pu on 50 MVA base (same kV base). On 75 MVA base, pu reactance is:

0.227 pu

0.253 pu

0.19 pu

0.207 pu

#101. [Probability and Statistics] A lot has independent defect probability 0.03 per board. For 12 boards, what is P(at least 2 defect)?

0.04

0.036

0.049

0.057

#102. [Circuit Analysis] A Thevenin source Vth=32 V with Rth=12 Ω feeds RL=20 Ω. Load current is:

0.82 A

0.75 A

1.25 A

1 A

#103. [Engineering Economics] What present value is equivalent to a future replacement cost of $57,328 in 8 years at 9%?

28771.0 USD

33949.8 USD

35963.7 USD

21578.2 USD

#104. [Communications] Compared with pure FDM, which is a key advantage of CDMA in multipath-rich mobile channels?

It eliminates the need for synchronization entirely

Processing gain enables interference averaging and supports soft capacity

It requires fewer chips than symbols for spread-spectrum operation

It guarantees zero near-far effects without power control

#105. [Computer Networks] Ignoring loss, TCP throughput with receive window 128 kB and RTT 80 ms is approximately:

11.796 Mb/s

15.466 Mb/s

13.107 Mb/s

9.83 Mb/s

#106. [Linear Systems] For a 2nd-order system with damping ratio ζ=0.63 and ωn=6.97 rad/s, estimate 2% settling time.

1.08 s

1.007 s

0.751 s

0.915 s

#107. [Mathematics] A phasor is V = 7 + j7. What is |V|?

9.899

7.425

8.91

12.374

#108. [Ethics and Professional Practice] During RF testing, PPE requirements are being ignored in a high-field area. Your best professional response is to:

Record violations and address them at project closeout

Stop testing and enforce safety controls before resuming

Move only your own team out of the area

Continue if measured exposure is usually below limits

#109. [Mathematics] For first-order decay dy/dt = -2y with y(0)=1, find y(1.19 s).