 # Electronics Engineering Mastery Test 9: ECE Pre-Board

(Last Updated On: December 23, 2017) This is 100 items of Practice Examinations set 9 in Electronics Engineering composed of previous Board Exams Questions. Read each questions and choices carefully! Choose the best answer. In the actual board, you have to answer 100 items in Electronics Engineering within 5 hours. You have to get at least 70% to pass the subject. Electronics Engineering is 30% of the total 100% Board Rating along with Mathematics (20%), General Engineering and Applied Sciences (20%) and Electronics Systems and Technology (30%).

### Start the Test Yourself Exam 9

Choose the letter of the best answer in each questions.

1. What is the maximum number of electrons in a subshell?

• A. 2
• B. 6
• C. 10
• D. 14

Solution:

2. The repeatability of a servo-controlled robot is within _____ mm rather than a fraction of a mm.

• A. 2
• B. 4
• C. 3
• D. 5

Solution:

3. What is the principal quantum number of a Q shell?

• A. 6
• B. 5
• C. 4
• D. 7

Solution:

4. What time when the voltage across L will be equal to the voltage across R in a series RL transient circuit where E = 24 V, R = 10 Ω and L = 1 H?

• A. 69.3 ms
• B. 69.3 s
• C. 6.93 ms
• D. 6.93 s

Solution:

5. What is the hysteresis loss at a frequency of 60 cycles per second of an audio transformer magnetic core which has a maximum flux density of 10,000 gausses? The volume of solid iron of this core is 66.8 cubic cm and the hysteresis coefficient (a constant that depends upon grade and quality of iron) id 5.35 x 10-4.

• A. 0.5386 W
• B. 53.86 W
• C. 5.386 W
• D. 5386 W

Solution:

6. When two coils of equal inductances are connected in series with coefficient of coupling and their fields in phase, find the total inductance of two coils.

• A. 2LA
• B. 2LA (1+k)
• C. 2kLA
• D. LA (2 + k)

Solution:

7. A 2 μF capacitor with initial charge q0 = 100 μC, is connected across a 100 Ω resistor at t = 0. Calculate the time in which the transient voltage across the resistor drops from 40 to 10 V.

• A. 2.77 s
• B. 0.277 ms
• C. 2.77 ms
• C. 0.277 s

Solution:

8. What do you call a small D.C generator built into alternators to provide excitation current to field windings?

• A. prime mover
• B. excitor
• C. commutator

Solution:

9. What is the condition of the diode in a parallel-limiter when the output is developed?

• A. Shunted
• B. Conducting
• C. Cut-off
• D. Shorted

Solution:

10. What is the payload of the industrial robot AEA IRb-60?

• A. 60 kg
• B. 80 kg
• C. 50 kg
• D.70 kg

Solution:

11. Which of the following robot is primarily used for machining processes?

• A. Cincinatti T1
• B. Cincinatti T3
• C. Cincinatti T2
• D. Cincinatti T4

Solution:

12. The Kuka spot welding robot has how many degrees of freedom?

• A. 4
• B. 6
• C. 5
• D.7

Solution:

13. What system in industrial electronics has the ability to monitor certain variable in the industrial processes, the same can perform self-correcting action?

• A. Coal-slurry system
• B. Closed-loop system
• C. Open-loop system
• D. Feed forward control system

Solution:

14. What is the property of a gyro so that the axis of rotation or spin axis tends to remain in a fixed direction in space if no force is applied to it?

• A. Selectivity
• B. Precession
• C. Rigidity
• D. Sensitivity

Solution:

15. In a series RLC circuit with R= 200Ω L= 0.1 H and C= 5µF, find the transient current after the switch is closed at t=0 applying a 200V source.

• A. 2e^(-1000t)sin 1000t
• B. 2e^(-1000t)cos 1000t
• C. 2e^(-100t)sin 100t
• D. 2e^(-100t)cos 100t

Solution:

16. A 0.09 µF capacitor is charged to 220V. How long in milliseconds will it discharge to a level of 110V if the discharge resistor has a resistance of 20kΩ?

• A. 1.25
• B. 12.5
• C. 125
• D. 0.125

Solution:

17. What are the heavy particles that include the proton and the neutron?

• A. Mesons
• B. Baryons
• C. Leptons
• D. Quarks

Solution:

18. What particles have rest masses ranging down to about 0.1amu?

• A. Leptons
• B. Baryons
• C. Quarks
• D. Mesons

Solution:

19. By definition, what is the individual angular momentum of the neutron proton and electron?

• A. h/4π
• B. h/2π
• C. h/π
• D. 4πh

Solution:

20. In the hysteresis loop, what do you call the product of the residual magnetic flux and coercive field strength?

• A. Effectivity product
• B. Hysteresis coefficient
• C. Residual-coercive product
• D. Steinmetz’s product

Solution:

21. Programming of a continuous-path robot is normally carried out by a method called ______ through.

• A. See
• B. Walk
• C. Pull
• D. Push

Solution:

22. What do you call the strong magnetism that occurs in certain ceramic compounds such as ferrites?

• A. Ferromagnetism
• B. Ferrimagnetism
• C. Diamagnetism
• D. Paramagnetism

Solution:

23. What characteristic is determined by the time required for a voltage wave to travel from the input end of an electrical transmission line to the output end and back again?

• A. Pulse position
• B. Pulse line
• C. Pulse width
• D. Pulse code

Solution:

24. A disturbance similar to brownout but of shorter duration that occurs when the line voltage drops below 80-85% of its rated voltage by one or more cycles.

• A. Sag or dip
• B. Chronic overvoltage
• C. Spike
• D. Transient

Solution:

25. What term is given to the positions of the rotors of a synchro transmitter and the synchro receiver when both rotors are on a 0 degree displaced from 0 degree by the same angle?

• A. Correspondence
• B. Overlap
• C. Fine tune
• D. Stability 