家在线测试 CES Engine Support Test online CES 5.1 for Engine department, Support level

在线测试： Test online CES 5.1 for Engine department, Support level

选择测试模式：

教育

演练模式

在线测试

描述

该测试由有关选定主题的随机问题组成。

问题 1 从 90

Give the command after ga+ for the transmission of a ‘store and forward’ –message withradio-telex:

sta…+

tlxstf

tlx..+

stf…+

The following information must be given on the SART:

Date of replacement of the battries

The date of replacement of the hydrostatic release unit

The name of the operator

The MMSI number sent

In discussing the properties of chemical cargoes, what is the "Odor Threshold" of a product?

The smallest concentration, expressed in parts per million by volume in air, that can be detected by smell by most people.

The maximum concentration of a vapour that can be tolerated without permanent damage to the nasalmembranes.

The temperature at which the vapour pressure a substance is greater than the prevailing atmospheric pressure and vapour is then released into the environment.

The average concentration of a substance to which a worker may be repeatedly exposed for a normal 8 hour working day, 40 days a week, without adverse health effects.

You are duty officer on board a vessel in open sea. The look out is doing work and you are alone on the bridge, presently checking the position in the chartroom. Suddenly you are colliding with a fishing vessel. You will be most to blame for the collision, because of:

You should ask over VHF if there is any vessels in the surronding waters before going to the chart room.

You shall always give the "keep away" signal when doing chart work.

The fishing vessel should have kept away and you will not be blamed.

You did not maintain a proper look - out by all available means.

The vessel is to anchor with Pilot onboard. Which of the suggested answers most accurately define the main duties of the Officer of the Watch on bridge?

Monitor the bridge equipment and keep the Master informed of all outputs

Assist the Master and pilot and monitor the ships position.

Follow Pilots orders and ensure the anchorage is carried out successfully

Follow the Master's orders at all times.

What would be the stopping distance of a VLCC when proceeding at 8 knots in deep water and the engines are put 'Full Astern'?

8 nautical miles

4 nautical miles

15 ship lengths

Varies, but can be determined from trial data

*On board a ship, how many lifebuoys is required to be fitted with a buoyant lifeline ?

At least one lifebouy with buoyant lifeline on each side of the ship

Half of the total number of lifebuoys provided on board

Only the two lifebuoys of the quick-release system

The total number of lifebuoys provided on board

Which one of the listed requirements regarding liferafts does not correspond to present regulations? Every liferaft shall be so constructed that:

It's canopy has viewing ports in all directions

It can be dropped from a height of at least 18 metres

It can be towed at a speed of 3 knots with full complement

It can withstand repeated jumps from a height of 4.5 metres

What kind of safety equipment must be worn during anchoring?

All of the mentioned equipment.

Boiler suit, working gloves.

Safety helmet, safety shoes.

Safety goggles.

"A contractor is hired to install new navigation equipment onboard your ship while it’s berthed. For a period of time he’s left unsupervised and photographs schematics of the ship that he finds rolled up and stored in the corner of a nearby office. Later, from home, he hacks into the network and prints off information about the ship’s security procedures. Which of these information security measures would have prevented his unauthorized access?"

"Protective markings, reference checks, and passwords."

"Secure area, passwords, a firewall and a secure network."

"Firewall, protective markings, vetting and a secure network."

"Secure area, passwords, a firewall and protective markings."

Why do blunt knives cause accidents?

Because they will need to be held at a more shallow angle when cutting.

Because the blunt edge will contain grease particles.

Because they require more pressure to be used and are more likely to slip.

Because the handles are more likely to be loose.

Some 4-stroke engines are fitted with a rotorcap on the cylinder head valves. For what reason?

Rotate the inlet valve during operation.

To prevent the valve spindel to stick..

Distribute the exhaust gas or the air inlet better to improve combustion.

Improve the scaling surface function, increase the service time of the exhaust valve in the engine.

Which of the following is not a principle of heat transfer utilised in a boiler?

Ionisation.

Conduction.

Convection.

Radiation.

Many marine steam boiler designs incorporate external "downcomers". What is the main purpose of these downcomers?

To provide extra support for furnace tubes.

To increase heating surface area.

To ensure adequate circulation in all boiler operating conditions.

To provide a flow path for the steam bubbles.

What is "spiked crude oil"?

A group of naturally occurring organic chemicals containing sulphur?

A crude oil where some gas is removed?

A crude oil blended with a liquefied gas or condensate?

A term used to

On the figure 4 possible definitions of the term "LENGHT OVERALL" are given. Which one is the correct one?

Lenght overall is given by C on the figure

Lenght overall is given by B on the figure

Lenght overall is given by A on the figure

Lenght overall is given by D on the figure

When first using cleaning agent in the machinery space, the crew should:

Confirm that it won't form an emulsion

Use it sparingly

Use it liberally

Confirm that it will form an emulsion

Severe piston ring and liner wear are experienced in two cylinders of a medium speed diesel engine shortly after a complete overhaul of all of the cylinders of the engine. The engine is fitted throughout with chrome plated cylinder liners. Which of the given options is the most likely cause of the excessive wear in the two cylinders?

The oil control rings have been fitted upside down in the two cylinders.

Chrome plated piston rings have been mistakenly fitted to the two cylinders.

Cast iron piston rings have been mistakenly fitted to the two cylinders.

The running in period for the engine was too short.

What does crude oil consist of?

A natural mixture of carbon and sulphur isomers.

A mixture of carbon extracts and naturally occuring wax.

A natural mixture of simple and complex hydrocarbon compounds.

A refined blend of hydrocarbon compounds and sulphur extracts.

What pressure is present in the crankcase of a vapour compression refrigeration compressor?

The same as the discharge pressure.

The same as the atmospheric pressure.

The same as the lubricating oil pressure.

The same as the suction pressure.

When opening hatch covers on a General Cargo vessel, what would indicate that there was ingress of water into the cargo holds during the voyage?

Rust-stained cargo

Evenly-distributed rust spots around the cargo hold

Evenly-distributed rust spots on cargo

Bright rust streaks on hatch coamings

Pump rooms on oil tankers shall be provided with a fixed fire-extinguishing system. Which of the following systems is in accordance with present regulations? (SOLAS II-2/63)

Fixed pressure water spraying system

Fixed high expansion foam system

Fixed CO2 fire-extinguisher system

Fixed powder fire-extinguishing system

The chemical abbreviation "H2S" is often associated with Crude Oil cargoes. What does the abbreviation stand for?

Hydrogen Sour.

Hydrogen Separation - 2nd distillation stage.

Hydrogen Sulphide.

Halogenated Sulphide.

What is the correct location or working station for the deck watchman during cargo operations on an oil tanker?

In the cargo control room.

Available somewhere on the weather deck only.

Standing by in the crew mess.

On the cargo tank deck at all times.

Some gas carriers are designed to carry both LPG and LEG. What is the design temperature on the cargo containment system on a LPG/LEG carrier?

Design temperature of the cargo containment system for an LPG/LEG carrier is minus 103 degrees C

Design temperature of the cargo containment system for an LPG/LEG carrier is minus 48 degrees C

Design temperature of the cargo containment system for an LPG/LEG carrier is minus 89 degrees C

Design temperature of the cargo containment system for an LPG/LEG carrier is minus 162 degrees C.

How should caterpillar crawlers stowed on hatch covers be secured?

By means of wire ropes secured to the hatch covers from all four sides of the unit

By means of wire ropes secured to the main deck from all four sides of the unit

By means of wire ropes secured to the hatch coamings

By means of wire ropes secured to the hatch covers and to the main deck from all four sides of the unit

On what criteria is the Threshold Limit Value (TWA) based?

The maximum concentration of a vapour to which a worker may be repeatedly exposed for a maximum of 12 hours per day, 5 days per week without serious health effects.

The concentration of a vapour expressed as a percentage of the oxygen content of an environment in which a fit human-being can work continuously for a period of 8 hours.

The time-weighted concentration of a substance to which a worker may be repeatedly exposed for a normal 8 hour working day and 40 hour week without adverse health effects.

The maximum concentration of harmful vapour to which a worker may be exposed for a period of 15 minutes up to 4 times within any 24 hour period without adverse respiratory effects.

On a container vessel select from the list the direction of wave encounter which is most likely to cause a parametric roll.

Head seas

On the beam.

Broad on the bow, just forward of the beam.

bow or stern quartering

A refrigerated container is loaded on deck. On inspection it is noted that the door seals are damaged. Select, from the options given, the main reason why it is unacceptable to have a refrigerated container in such a condition.

If the door seal is damaged the cargo packaging may become watermarked.

If the door seal is damaged the cargo may spoil due to ingress of warm air.

The refrigeration unit will run for more time than is normal.

The refrigeration unit will ice up to a greater extent than normal.

When should you use safety goggles?

When you are filling in the engine room log book.

When you are welding.

When you are tidying up in the engine room workshop.

When you are working with power tools or chemicals.

Why should a heavy lift derrick not be operated close to the horizontal?

Because the topping lift sheave may fail

Because the derrick gooseneck might crack

Because the topping lift wire may part

Because there is danger of the derrick heel springing out of its shoe

Is there any requirements regarding double bottom for large passenger ships?

Yes, in ships of 76 m in length and longer, a double bottom shall be fitted amidships, and extend to the fore and aft not less that ? of the ship length.

No, a double bottom is not required

Yes, in ship of 76 m in length and upwards, a double bottom shall be fitted amidships, and shall extend to the fore and after peak bulkheads, or as near thereto as practicable.

Yes, a double bottom shall be fitted amidship

Four similar ship-types experience beam sea conditions. Which of them will first experience resonant rolling?

The ship with the widest beam

The ship with the smallest GM

The ship with the highest freeboard

The ship with the smallest beam

Which vitamin is to be found only in foods from the animal kingdom?

Vitamin C

Vitamin E

Vitamin A

Vitamin B

A high pressure boiler is operating with all parameters normal except that the firing rate is high and the superheater temperature is high. Which of the options given is the likely cause of this condition?

The generating and screen tubes are fouled.

The de-superheater control is not operating correctly.

Insufficient combustion air is being supplied.

The superheater tubes are fouled.

In a crisis, which crew behaviours are most reassuring to passengers?

keeping up with safety knowledge

enthusiasm, confidence, hospitality

dependability

enthusiasm, confidence, decisiveness

In what format will an On-Scene Co-ordinator report such information as on-scene weather and operation progress to other parties?

SITREP.

OSCREP.

POSREP.

SARREP.

The instrument air system is suffering from excess water carry over to the instrument air lines. The air intake to the compressor has very high humidity. Which of the actions given in the options will most likely result in reducing this problem?

Use an additional coalescer filter in the inlet to the instrument air filter system.

Shorten the time between automatic receiver drain blow downs.

Reduce the superheat setting on the instrument air refrigeration/dryer unit.

Increase the cooling water flow through the compressor intercooler and aftercooler.

What does the term liquefaction mean with respect to some heavy metal concentrate cargoes on a Bulk Carrier?

The cargo is very dry and will not reach a flow state

The cargo may suffer moisture migration and become semi-liquid near the top of the stow

The cargo may self-heat on voyage

The cargo pile will always be stable

During loading of bananas the fruit should be visually inspected frequently to check the quality and for any indications as to its physiological development. Which one of the options given would indicate that the fruit is in suitable condition for shipment?

The bananas are green with a yellow hue. They are not really hard and do not break cleanly.

The bananas are green in colour with patches on the shoulder from the effects of sunshine and have relatively sharp ridges along the length. They can be snapped with sap clinging to the broken parts.

The bananas are yellow with small black spots on the skin. They cannot be snapped but the skin can be peeled off.

The bananas have a uniform green colour with relatively sharp ridges along the length. They can be snapped or broken with sap clinging between the broken parts.

Ships officers must use a thermometer to take and record the pulp temperature of commodities being loaded onto a reefer vessel. From the given options, select the most important attribute of such a thermometer.

It must be portable.

It must be correctly calibrated.

It must be robust.

It must be economic to purchase.

Before loading operation starts, what shall you as duty officer observe?

The hoistable decks in correct positions and stanchion-guard placed where needed?

The angle on the stern ramp in order?

Leave everything to the crew?

Physical checking the ramp/cargo holds/hoistable decks and see that everything are in order and the ship-s gear correctly located?

When there is doubt about the freshness of the atmosphere in enclosed or confined spaces, what action should be taken?

Open doors and manholes

Arrangements should be made for testing of the atmosphere to ensure maintenance of 21% oxygen of the space

Ro-ro decks are always ventilated in advance of an operation

Supply filter masks to all crew working on ro-ro deck

Where would you look to find details of the crude oil washing system, its equipment and operating procedures? ,

The Operations and Equipment Manual (COW Manual).

MARPOL 73/78.

The Oil Record Book.

The ODME Manual.

How should steel wire rod coils be stowed?

With their cores aligned athwartships

With their cores aligned vertically

With their cores aligned fore and aft

With their cores aligned alternately fore and aft and athwartships

Most fuel oil separtors working on the centrifuge principle have an automatic start up and sludging facility. Which of the following actions would you expect to occur first during the start up sequence?

Sealing water supplied to bowl to prevent carry over.

Operating water drained from bowl to open it.

Operating water supplied to bowl to close it

Fuel oil supplied to bowl to fill it.

What term is applied to the arrangement by which liquid chemicals are stowed on board, so that potentially reactive chemicals are not placed in adjacent compartments?

Segregation.

Diversification.

Pre-stowage.

Separation.

A medium speed diesel engine, operating on heavy oil has suffered repeated exhaust valve failure. Upon inspection damage is noted on the underside of the valve resulting in some cases in holes passing through the valve even though the seating face appears hardly damaged. Which of the given options is the most likely cause of this type of damage?

High temperature corrosion due to high vanadium content in the fuel oil.

Failure of the valve rotators causing distortion of the valve seat.

Incorrect tappet (rocker arm) clearance preventing the valves from closing properly.

Cold temperature corrosion due to high sulphur content in the fuel and incorrect grade of cylinder lubricating oil.

Do we find integral tanks as cargo tanks on gas carriers?

Integral tanks are normally not allowed on gas carriers other than LPG carriers

Integral tanks are allowed on all types of gas carriers

Integral tanks are normally not allowed on gas carriers if the cargo to be carryed have boiling point less than –10oC at atmospheric pressure

Integral tanks are normally allowed on gas carriers if the cargo to be carryed have temperature above –10oC

How can you arrange for safe movement of passengers on ro-ro decks?

It is easy, only drivers are allowed to stay in the car during loading and unloading.

Passengers are responsible for their own safety while moving about ro-ro decks.

Passengers should be warned of vehicle movements when entering or crossing car or vehicle decks. They should preferably keep to walkways while moving about the ship.

Passengers should stay in their cars until loading is completed. They should keep to walkways when leaving the car.

What is the approximately efficiency of the ejector?

The ejector's efficiency is between 60% and 70%.

The ejector's efficiency is between 30% and 40%.

The ejector's efficiency is between 70% and 80%.

The ejector's efficiency is between 20% and 30%.

How can the pressure be regulated during start up of a positive displacement pump such as a gear pump?

By throttling the discharge valve

By throttling the suction valve.

Positive displacement pumps operate at constant pressure and cannot be regulated.

Adjustment of the pressure relief valve to recirculate part of the flow.

What is the connection between ethylene gas and food?

Ethylene is the gas that develops as yeast dough bakes

Ethylene is the gas given off by most fruits and vegetables during the ripening process

Ethylene is the gas that develops as baking powder dough bakes

Ethylene is the gas that develops when meat and fish are stored for too long (bacterial decomposition)

What is essential to ensure that efficient stripping of ballast tanks on a Bulk Carrier can be achieved?

A good stern trim is maintained during de- ballasting operations

The trim of the vessel is not important

A trim by the bow is required

The vessel must be maintained at an even keel

Which ideal heat engine cycle is the vapour-compression refrigeration system based on?

The Otto cycle.

The Rankine cycle.

The Dual cycle

The reversed Carnot cycle.

The cargo containment system for some LNG carriers is in the form of spherical tanks. What is the IMO classification for this type of tank?

Spherical self-supporting, type "A” tanks.

Spherical non-self-supporting, type "C" tanks.

Spherical tanks with full secondary barrier.

Spherical self-supporting, type "B" tanks.

What is the approximate normal daily cargo "boil off" rate for an LNG carrier of 125000 cubic metre cargo capacity?

From 0,75 % to 0,80 % per day of total cargo.

From 0,30 % to 0,35 % per day of total cargo.

From 0,15 % to 0,20 % per day of total cargo.

From 0,01 % to 0,05 % per day of total cargo.

What is the direction of wind associated with an anticyclone (area of high pressure) in the Northern Hemisphere?

Clockwise around the high pressure

Straight towards the centre of the anticyclone

Directly away from the centre of the anticyclone towards the nearest Low pressure.

Anticlockwise around the high pressure

A general cargo ship is discharging and smoke is reported coming from a hold which is not being worked at present; what action must be taken ?

Sound general alarm, call shore fire services and check number of persons on board

Enter space to access problem

Boundary cool adjacent spaces

Open hatch cover and attack with fire hoses

Is it required to have supplementary emergency electric lighting on board ro-ro ships?

No, portable battery operated lamps shall be provided in alleyways and public spaces

No, reflective marking indicates the escape routes

No, passengers should bring their own flashlights

Yes, all passenger public spaces and alleyways shall be provided with supplementary electric lighting

When carrying out repair or maintenance tasks involving hot work a hot work permit must be issued. Select the correct option from those given which completes the following statement. 'The permit for hot work…

..is valid for completion of the specific hot work tasks irrespective of the time taken.'

..can cover any additional hot work that arises during the completion of the task during the specified time period.'

..should only cover specific hot work tasks and be valid for a specified time period.'

..should only cover specific hot work tasks, be valid for a specified time period and be issued by the person carrying out the work.'

Hydrogen sulphide is a component associated with crude oil cargoes. At which of the following concentrations will dizziness, headache, nausea, etc occur within 15 minutes, followed by loss of consciousness and possibly death, after 30-60 minutes exposure?

50-70 ppm.

1,000 - 2,000 ppm.

200-300 ppm.

500-700 ppm.

Anyone who without valid reason places, removes, changes or conceals nationality marks or registration marks of a registered ship shall be liable to???

Imprisonment for a term not exceeding 6 months.

Fines or imprisonment for a term not exceeding 12 months.

Fines or imprisonment for a term not exceeding 6 months.

Fines.

Which of these measures would you implement to prevent drugs from being smuggled onboard your ship while it’s berthed?

"Search some of the packages, spares and stores received."

Maintain restricted areas.

Check a portion of the bags and packages brought onboard.

Eliminate fore and aft deck watch at night.

What is the purpose of the "Spray Line" as fitted in the cargo system of an LNG carrier?

It is used for cooling down the cargo lines and cargo tanks prior to cargo operation.

It is used for cooling down the inter-barrier spaces.

It is used for cooling down the void spaces and cofferdams.

It is used to flush the deck in case of cargo overflow.

As per SOLAS a fast rescue boats shall be capable of:

Manoeuvring for at least 8 hrs at a speed of 10 knots

Manoeuvring for at least 4 hrs at a speed of 20 knots in calm water

Manoeuvring for at least 4 hrs at a speed of 8 knots

Manoeuvring for at least 4 hrs at a speed of 4 knots

Indicate the correct name for the part marked on the sketch:

Air cooler

Cylinder head

Crankshaft

Turbocharger

Why should cargo holds be swept completely prior to washing on a bulk carrier?

Because it is a requirement under MARPOL 73/78

So that cargo residues will not be pumped overboard

Because it is part of a company's safety management system

So that cargo residues will not clog the bilge lines and associated suctions and valves

Which of the following options may be used as a brief summary of how to safely make high voltage equipment accessible?

Shed load, Earth (ground), disconnect, isolate

Disconect, isolate, earth (ground)

Shed load, isolate. Earth (ground)

Disconnect, earth (ground), isolate

Which of the given options is IMO's definition of liquefied gas as used in its Gas Codes?

Liquid with vapour pressure exceeding 2.8 bar absolute at a temperature of 73.8 C.

Liquid with vapour pressure exceeding 2.8 bar absolute at a temperature of 37.8 C.

Liquid with vapour pressure exceeding 1.8 bar absolute at a temperature of 38.7 C.

Liquid with vapour pressure exceeding 1.8 bar absolute at a temperature of 87.3 C.

When there is doubt about the freshness of the atmosphere in ro-ro cargo spaces, what action should be taken?

Supply filter masks to all crew working on ro-ro deck

Ro-ro decks are always ventilated in advance of an operation

Arrangements should be made for testing of the atmosphere to ensure maintenance of 21% oxygen and a carbon monoxide content below 50 ppm in the atmosphere of the space

Open both bow- and stern doors

Select, from the options given, the best method to be used for cleaning a cargo space on a conventional reefer vessel into which the cargo to be loaded is the same as the previous cargo carried.

A quick blow through on the top of the deck gratings with compressed air.

Sweep clean the top of the hatch gratings and lift the gratings to sweep clean below them.

A quick blow through on top of and below the deck gratings with compressed air.

A complete wash down of the cargo space with a suitable cleaning agent.

What is understood by the term "Dew point" of the air?

The temperature at which condensation in the air forms into water droplets.

The temperature of the water vapour in a cloud.

The "Dew Point" is the point at the centre of an Anticyclone

All of the suggested answers

Which is the "CAPSTAN", in the figure?

The Capstan is indicated by A, in the figure

The Capstan is indicated by D, in the figure

The Capstan is indicated by C, in the figure

The Capstan is indicated by B, in the figure

What is ‘Reserve Buoyancy’?

The buoyancy provided by all enclosed spaces above the waterline

The residual buoyancy at an angle of loll

The residual buoyancy at the maximum righting lever

The buoyancy provided by all spaces above the waterline

A resistor has three red bands. What is the resistance?

220 ohm

22 ohm

2200 ohm

222 ohm

Why did the new Cadet want to go to the messroom?

The new Cadet wanted to go to the messroom to sign the Articles of Agreement

The new Cadet wanted to go to the messroom to get some rest

The new Cadet wanted to go to the messroom to become acquainted with the officers

The new Cadet wanted to go to the messroom to check that his papers were in order

Many gas carriers are designed to carry liquefied petroleum gas (LPG). How is LPG defined in the IMO Gas Codes?

LPG is defined as butane and ethane or a mixture of both.

LPG is defined as propane and butane or a mixture of both.

LPG is defined as propane and ethane or a mixture of both.

LPG is defined as propane and methane or a mixture of both.

What would you do before giving a boiler a “bottom blow”

drop the water level a couple of inches below normal

increase the oil pressure

raise the water level a couple of inches above normal

increase the oil temperature

While on boiler watch in the engine room a rating is requested to assist with taking on stores. The task will take about half an hour. What should the rating do?

Just ignore the request to assist with the stores.

Go and help with the stores but go back and check the boiler every 10 minutes.

Raise the boiler water level above normal to make sure there is sufficient water while he is busy with the stores.

Contact the engineering officer of the watch for permission to assist and to arrange a relief for the duration of the store taking.

During a walk around of a stow of refrigerated containers, one of the containers is noted to be quiet and has a red light showing on the control panel. Select, from the options given, the most likely cause of this condition.

The red light indicates that there is power to the container.

The red light indicates that an air change is in progress.

The red light indicates that there is a fault with the container's refrigeration unit.

The red light indicates that there is no power to the container.

What special requirements applies to fire alarm signalling systems in passenger ships

Remote control of fire doors and reactivation of ventilation

Same requirements for Fire alarm systems applies to all ships

Centralized in a continuously manned control station with remote control of fire doors, Indication of open or closed fire doors

Fail safe, Centralized in a continuously manned control station, Remote control of fire doors, Indication of open or closed fire doors, Reactivation of ventilation, Detector status, Back up powered

Most medium and high speed diesel engines operate with mean piston speeds greater than those for larger slow speed engines. What is the main design feature of these engines which allows the higher mean piston speeds to be achieved without causing unwanted failures?

Using composite pistons featuring steel crowns and alloy skirts

Fitting bronze rubbing bands to the piston skirts.

Using directly cooled piston crowns with long piston skirts.

Using cast iron single piece piston crowns with a short piston skirt.

What is the greatest danger associated with the carriage of chemicals?

Leakage from the carrying receptacles

Outbreak of fire

Evaporation

Reaction with the carrying receptacles

On which type of gas carrier can spherical tanks be used for the cargo system?

Spherical cargo tanks can be used for fully refrigerated, semi-pressurised/semi-refrigerated and fully pressurised gas carriers.

Spherical cargo tanks are only used for fully pressurised gas carriers

Spherical cargo tanks are only used only for semi-refrigerated gas carriers

Spherical cargo tanks are only used for fully refrigerated and semi-refrigerated/semi-pressurised gas carriers

This device can detect a package of drugs inside a large delivery of ship’s stores. What is it?

Vapour detector

Pallet scanner

Security container

Access control system

This circuit consists of a current source I, a change-over switch S, a resistor R and a capacitor C. The current/time figures 1 to 4 show possible changes in the current I in case the switch S is suddenly shifted from position 1 to 2 at time t= 0. Only one of the diagrams is correct. Which?