Free USCG-CE-LTD Practice Questions

Question 1

Following replacement of No. 4 injection pump on a mechanically injected diesel, the engine is returned to its previous steady speed and load. No. 4 exhaust temperature is now 70°C above the other cylinders. Its compression pressure is unchanged, but peak firing pressure is lower and occurs later in the expansion stroke. Common charge-air pressure and the other cylinders' readings are unchanged. Which fault best explains the combined findings?

Accepted Answer

Retarded injection timing on the replacement fuel pump.

Answer

Leakage past No. 4 cylinder's exhaust valve.

Answer

Injection beginning too far before top dead center in No. 4 cylinder.

Answer

A restricted common turbocharger air intake.

Question 2

Two identical alternators are paralleled on an isolated 440 V, 60 Hz shipboard bus. Each supplies 250 kW, but No. 1 supplies 210 kVAr while No. 2 supplies 70 kVAr. Both are within their ratings. The engineer wants to equalize reactive load while retaining the present real-power sharing. Which paired adjustment is appropriate?

Accepted Answer

Decrease No. 1 excitation and increase No. 2 excitation.

Answer

Raise No. 1 governor load setting and reduce No. 2's.

Answer

Increase No. 1 excitation and decrease No. 2 excitation.

Answer

Reduce No. 1 governor load setting and raise No. 2's.

Question 3

A non-tanker is discharging treated machinery-space bilge water in U.S. navigable waters. Its approved oil-content monitor reads 8 ppm without dilution, but a visible oil sheen is traced to the discharge outlet. There is no flooding emergency. What should the engineer do about the overboard discharge?

Accepted Answer

Stop it; the visible oil sheen is unacceptable despite the reading below 15 ppm.

Answer

Continue while an independently collected effluent sample is tested to check the oil monitor's accuracy.

Answer

Continue at the existing rate because the measured oil content is below 15 ppm.

Answer

Reduce the discharge rate until the sheen disappears, then retain that setting.

Question 4

A centrifugal pump takes freshwater from a large tank open to atmosphere. At the planned flow, atmospheric pressure is equivalent to 10.3 m of water, the tank surface is 2.0 m below the pump centerline, suction losses are 1.1 m, and vapor-pressure head is 0.2 m. The pump requires 4.0 m NPSH, with an additional installation margin of 0.8 m. Its discharge duty requires 18 m total head. Considering suction capability, which assessment is correct?

Accepted Answer

Available NPSH is 7.0 m, exceeding the required 4.8 m including the installation margin.

Answer

Available NPSH is -3.3 m; the open tank cannot provide the required suction head.

Answer

Available NPSH is 7.0 m; the pump fails because this is below its 18 m duty head.

Answer

Available NPSH is 11.0 m; the required suction margin is satisfied.

Question 5

A water-tube boiler experiences rapid steam-load changes. When demand increases, drum pressure falls and indicated level initially rises even though steam outflow exceeds feedwater inflow. The shared feedwater header also has pressure fluctuations. To address both disturbances, which three measurements belong in the feedwater-control scheme?

Accepted Answer

Drum level, steam flow, and feedwater flow.

Answer

Drum level, feedwater temperature, and feed-valve position.

Answer

Drum level, steam flow, and pressure at the feedwater-pump discharge.

Answer

Drum level, steam pressure, and fuel-oil flow.

Question 6

A marine gas turbine's starting instructions require flame within 10 seconds of fuel admission and gas-generator speed of 60% within 40 seconds after light-off. The starting exhaust-temperature limit is 650°C. Flame is proved after 5 seconds. At 45 seconds after light-off, gas-generator speed remains at 43% and exhaust temperature is steady at 560°C. How should this start be classified and handled?

Accepted Answer

Hung start; shut off fuel and investigate the failure to accelerate.

Answer

Normal acceleration; continue the start while measured temperature remains below its limit.

Answer

Failed light-off; abort and investigate failure to establish combustion.

Answer

Hot start; abort and investigate excessive starting temperature.

Question 7

At steady engine load with fully warmed oil, differential pressure across the duty chamber of a duplex lubricating-oil filter reaches 0.9 bar; the specified changeover limit is 0.7 bar. Engine-inlet oil pressure and bearing temperatures remain normal, and the bypass has not opened. A clean standby chamber is ready, and the filter is designed for on-load changeover. Select the next filter action.

Accepted Answer

Transfer oil flow to the clean chamber, then isolate and depressurize the dirty side.

Answer

Reduce engine speed until differential pressure clears, keeping the same filter chamber selected.

Answer

Stop the engine before changing both elements and restoring lubricating-oil circulation.

Answer

Wait for automatic bypass to open before taking the dirty chamber out of service.

Question 8

A vessel displaces 1,200 tonnes. In this loading condition, transverse KM is 3.40 m and KG calculated with the liquids treated as solid weights is 2.70 m. The only slack tanks have free-surface moments of 180 and 360 tonne-metres. Which corrected transverse GM and initial-stability assessment should be reported?

Accepted Answer

+0.25 m; a positive initial restoring tendency.

Answer

-1.15 m; an unstable equilibrium when upright.

Answer

+0.70 m; a positive initial restoring tendency.

Answer

+1.15 m; a positive initial restoring tendency.

Question 9

The control-room pressure display drops to 0 bar on a channel using a linear 4-20 mA transmitter ranged 0-10 bar. Measured loop current is 0 mA. An independent calibrated gauge at the same header reads 4 bar, and pump delivery remains steady. What does the zero-current reading establish before any calibration adjustment?

Accepted Answer

The current loop is no longer providing a valid pressure signal.

Answer

The transmitter span must be reduced to match the independent gauge.

Answer

A valid zero-pressure signal is reaching the control-room display.

Answer

The header has depressurized and the independent gauge is responding slowly.

Question 10

A double-acting hydraulic cylinder has a rod on one side of its piston. Pressure is applied to one chamber while the other returns directly to tank. With the same supply pressure and delivered flow in either direction, and negligible return pressure, how does retraction compare with extension?

Accepted Answer

Retraction is faster and produces less force at that pressure.

Answer

Retraction is faster, with no change in the force available.

Answer

Retraction is slower because the rod increases the working piston area.

Answer

Retraction has unchanged speed but develops less force.

Free USCG-CE-LTD Practice Questions

Domain 1: Q601 General Subjects

Question 1

Question 2

Domain 2: Q602 Motor Plants

Question 3

Question 4

Domain 3: Q603 Engineering Safety and Environmental Protection

Question 5

Question 6

Domain 4: Q604 Electricity, Electronics and Control Engineering

Question 7

Question 8

Domain 5: Q605 Steam Plants

Question 9

Domain 6: Q606 Gas Turbine Plants

Question 10

That's 10 of 1,030