COMPETENCE 7 – Maintenance and Repair of Electronics and Electrical Equipment
#1. Electrical wire in general, when used aboard vessels must meet minimum requirements. Which of the following statements is/are correct?
Incorrect!
#2. Compared to the original wire, what will be the resistance of a replacement wire having twice the length and one-half the cross-sectional area of the original?
Incorrect!
#3. For what purpose are thermal strip heaters provided in DC main propulsion motors?
Incorrect!
#4. Due to the operating characteristics of the system, time lag fuses (or dual- element fuses) are necessary for use in what types of circuits?
Incorrect!
#5. Compared to the fuse being replaced, what should be the characteristic of the replacement fuse for a fuse that blows often?
Incorrect!
#6. During discharge of a lead-acid storage battery, which of the following actions occurs?
Incorrect!
#7. DC generator circuits are protected against malfunctions due to prime mover power loss by the use of what device (or devices)?
Incorrect!
#8. Diesel generators #1 and #2 are operating in parallel at near full load capacity. Diesel generator #1 suddenly trips out mechanically due to low lube oil pressure. The reverse power relay functions properly and trips generator #1 electrically off the board. Which of the following actions should you carry out FIRST?
Incorrect!
#9. Consider a series circuit employing two resistors. What is true about the resistance value of the second resistor compared to the first when the voltage drop across the first resistor is one half the source voltage?
Incorrect!
#10. How are AC and DC generators are similar?
Incorrect!
#11. Consider a three-phase squirrel cage induction motor rated at 450 VAC and60 Hz. What would happen to the motor if the line frequency dropped from the normally supplied 60 Hz to 55 Hz and the voltage remained normal at 450 VAC.
Incorrect!
#12. D.C. propulsion motor brush pressure depends on the brush grade used. In practice with what device is the proper brush pressure established?
Incorrect!
#13. Compared to conventional alternators, brushless alternators are designed to operate without the use of what?
Incorrect!
#14. How are fuses rated?
Incorrect!
#15. Capacitors can be used in electric distribution systems to improve power factor. This is accomplished by seesawing energy between the capacitor and what device or devices?
Incorrect!
There are 15 questions for the actual examination for Competence 7 for OIC-EW with a passing rate of 70%. This means that you are only allowed to make 4 mistakes.
DISCLAIMER
The questionnaires contained in this “reviewer” are extracted from the post released by MARINA on their official website and other review materials. Please note that Seaman Kowts is not affiliated with, endorsed by, or connected to the official website of MARINA. The information provided on this website is for general informational and educational purposes only and should not be relied upon as official or authoritative. If you require official information or services, please visit the official website or any relevant review center. We do not assume any responsibility or liability for any consequences resulting from the use of information or services provided on this website.