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Past Questions — 2025
What does the breakdown voltage test of transformer oil measure?
A)
The oil level inside the transformer
B)
The cooling efficiency of the oil
C)
The insulation strength of the oil
D)
The temperature rise of the winding
The breakdown voltage (BDV) test is a critical diagnostic test performed on transformer insulating oil. The primary purpose of transformer oil is twofold: to provide cooling and to act as an electrical insulator between the windings and the tank. The BDV test involves applying an increasing voltage across two electrodes immersed in the oil sample until a spark (electrical breakdown) occurs. The voltage at which this occurs indicates the dielectric strength of the oil. A low BDV value typically indicates the presence of contaminants such as moisture, dissolved gases, or particulate matter, which reduce the oil's ability to resist electrical stress.
Why other options are incorrect:
- Option (a): Oil level is measured using a physical oil level gauge or conservator tank sight glass, not through a voltage test.
- Option (b): Cooling efficiency is related to the oil's thermal conductivity and viscosity, measured through heat dissipation tests or flow rate analysis.
- Option (d): Temperature rise is measured using thermometers or thermal imaging, not by applying high voltage to the oil.
In internal wiring, what determines the size of wire to be used?
A)
Room size
B)
Load Current
C)
Number of lights
D)
Wall thickness
In electrical wiring, the primary factor that determines the gauge or size of the conductor (wire) is the amount of current it must carry, known as the Load Current. This is based on the principle of current-carrying capacity (ampacity). If a wire is too thin for the load current, it will overheat due to resistance (I²R losses), which can melt the insulation and lead to electrical fires.
Why other options are incorrect:
- a. Room size: While room size might influence the length of the wire (affecting voltage drop), it does not determine the thickness/size of the wire itself.
- c. Number of lights: The number of lights is a component of the total load, but the determining factor is the total current (Amperes) those lights draw, not the count of fixtures.
- d. Wall thickness: Wall thickness affects the installation method (conduit routing) but has no bearing on the electrical capacity or size of the conductor required.
HDPE pipes are mostly preferred for:
A)
Electrical wiring
B)
Portable water supply due to flexibility
C)
Sewer lines only
D)
Road construction
HDPE (High-Density Polyethylene) pipes are widely preferred for potable (drinking) water supply systems for several technical reasons: 1. Flexibility: They can bend to accommodate terrain changes, reducing the need for numerous joints and fittings. 2. Corrosion Resistance: Unlike metal pipes, HDPE does not rust or corrode, making it ideal for transporting clean water. 3. Durability: It is resistant to chemical degradation and impact. 4. Leak-proof joints: Heat-fused joints create a monolithic system that prevents leakage.
Analysis of other options:
- Option (a): While HDPE is used as a conduit for electrical cables, the context of the exam (Public Health Engineering Department - Water Supply topic) makes water supply the primary intended answer.
- Option (c): While HDPE can be used for sewers, it is not used 'only' for sewer lines; it is a primary choice for pressurized water mains.
- Option (d): HDPE is not a material used for road construction itself, although it may be buried beneath roads.
Which tool helps in identifying continuity in cables and connections?
A)
Earthing rod
B)
Test lamp
C)
Hydrometer
D)
Clamp Meter
Continuity testing is the process of checking whether an electrical circuit is complete (closed) or broken (open).
1. **Test Lamp (Correct):** A test lamp is a simple device consisting of a light bulb and a power source. When connected across a cable or connection, if the circuit is continuous (closed), the lamp glows. If there is a break in the wire, the lamp remains off. This makes it a fundamental tool for identifying continuity in basic electrical troubleshooting.
2. **Earthing Rod (Incorrect):** An earthing rod is a metal rod driven into the ground to provide a low-resistance path for leakage currents to flow to the earth for safety; it is not used to test continuity.
3. **Hydrometer (Incorrect):** A hydrometer is used to measure the specific gravity (density) of liquids, most commonly used to check the state of charge in lead-acid batteries. It has no application in electrical continuity testing.
4. **Clamp Meter (Incorrect):** While a clamp meter can measure current (via induction) and some digital versions have a continuity buzzer, its primary purpose is measuring AC/DC current without breaking the circuit. In the context of basic tools for identifying continuity, a test lamp is the classic answer for simple 'go/no-go' connectivity checks.
Which routine task is essential for maintaining an Induction Motor?
A)
Changing rotor size
B)
Removing stator
C)
Replacing shaft
D)
Lubricating bearings
Routine maintenance refers to periodic, preventative tasks performed to ensure the longevity and efficiency of a machine without dismantling its core structural components.
1. **Lubricating bearings (Correct):** Bearings support the rotating shaft and are subject to friction and wear. Regular lubrication (greasing or oiling) is a standard routine task essential to reduce friction, prevent overheating, and avoid premature bearing failure.
2. **Changing rotor size (Incorrect):** The rotor size is a design specification determined during manufacturing. Changing it would require a complete redesign of the motor and is not a maintenance task.
3. **Removing stator (Incorrect):** The stator is the stationary part of the motor. Removing it involves a complete teardown (overhaul), which is an extraordinary repair measure, not a 'routine' maintenance task.
4. **Replacing shaft (Incorrect):** The shaft is replaced only in the event of a mechanical failure (e.g., bending or snapping). This is a corrective repair, not a routine maintenance activity.
Which of the following values indicates the best power factor?
A)
0.8
B)
0.5
C)
0
D)
1
Power factor (PF) is defined as the ratio of Real Power (kW) to Apparent Power (kVA), or mathematically as the cosine of the phase angle (cos φ) between the voltage and current.
1. Range of Power Factor: The value of the power factor ranges from 0 to 1.
2. Ideal Condition: A power factor of 1 (known as 'Unity Power Factor') indicates that the voltage and current are perfectly in phase. In this state, all the power supplied to the circuit is utilized as real power to perform useful work, and there is zero reactive power (kVAR) flowing in the system.
3. Efficiency: A higher power factor (closer to 1) is 'best' because it reduces current flow for the same amount of real power, thereby reducing energy losses (I²R losses) in transmission lines and improving the efficiency of the electrical system.
Comparing the options:
- 0: Worst possible power factor (purely reactive load).
- 0.5: Poor power factor.
- 0.8: Common acceptable power factor, but not the 'best'.
- 1: Ideal/Best power factor (Unity).
During lightning, what is the role of proper earthing in a pump house?
A)
Directs surge to ground safely
B)
Starts the motor automatically
C)
Reduces wire length
D)
Raises system voltage
Earthing (or grounding) is a safety mechanism used to protect electrical installations and personnel. During a lightning strike, a massive surge of high-voltage current is introduced into the system. A proper earthing system provides a low-resistance path that directs this electrical surge directly into the earth (ground), preventing the current from flowing through sensitive equipment (like pump motors and control panels) or through human operators.
Analysis of other options:
- Option b is incorrect because earthing is a passive safety system; it does not trigger the starting mechanism of a motor.
- Option c is incorrect because earthing involves adding grounding conductors, which does not reduce the length of the primary wiring.
- Option d is incorrect because the purpose of earthing is to stabilize voltage and prevent dangerous voltage spikes, not to raise the system voltage.
A submersible motor is suspected to have insulation failure. Which tool should be used to verify it before dismantling?
A)
Clamp Meter
B)
Megger
C)
Spanner set
D)
Slogging wrench
Step-by-step reasoning:
1. **Analyze the Requirement**: The question asks for a tool to verify 'insulation failure' in a submersible motor before dismantling it. Insulation failure occurs when the dielectric material separating the electrical conductors from the ground or other phases breaks down.
2. **Evaluate the Tool (Megger)**: A Megger (short for Mega-ohmmeter) is a specialized instrument used to measure very high electrical resistance, specifically insulation resistance. It applies a high DC voltage to the insulation to detect leakage currents. If the resistance reading is low, it confirms insulation failure.
3. **Evaluate Other Options**:
- **Clamp Meter**: Used primarily for measuring current (Amperes) flowing through a conductor without breaking the circuit. It cannot test insulation resistance.
- **Spanner set**: A mechanical tool used for tightening or loosening bolts/nuts. It is used during dismantling, not for electrical verification.
- **Slogging wrench**: A heavy-duty mechanical tool used for loosening stuck or large bolts by striking it with a hammer. It is not an electrical testing tool.
4. **Conclusion**: Since the goal is to test the integrity of the electrical insulation, the Megger is the only appropriate tool among the choices.
The device used to isolate a section of a transmission line during maintenance is
A)
Circuit Breaker
B)
Isolator
C)
Contactor
D)
Current Transformer
Step-by-step reasoning:
1. The primary requirement for maintenance is to ensure that the section of the line is completely disconnected from the power source to provide safety for personnel. This requires a visible physical break in the circuit.
2. An Isolator (also known as a disconnecting switch) is a mechanical switch used to isolate a part of the electrical circuit for maintenance purposes. Crucially, an isolator is an 'off-load' device, meaning it is operated only after the current has been interrupted by a circuit breaker.
3. Why other options are incorrect:
- a. Circuit Breaker: This is an 'on-load' device designed to interrupt fault currents (short circuits) or normal load currents. While it breaks the circuit, it does not provide a visible physical gap required for safety during maintenance.
- c. Contactor: This is an electrically controlled switch used for switching a power circuit (like a motor) frequently; it is not used for isolating high-voltage transmission lines for maintenance.
- d. Current Transformer: This is an instrument transformer used to step down high currents to a measurable value for metering and protection; it cannot isolate a line.
Which device is used to automatically break the circuit under fault conditions?
A)
Circuit Breaker
B)
Isolator
C)
Relay
D)
Capacitor
Step-by-step reasoning:
1. Analysis of the requirement: The question asks for a device that 'automatically breaks the circuit' during 'fault conditions' (such as short circuits or overloads).
2. Evaluating Option (a) Circuit Breaker: A circuit breaker is a mechanical switching device capable of making, carrying, and breaking currents under normal circuit conditions, as well as breaking currents under specified abnormal conditions (faults). It is designed to automatically interrupt the current flow to protect the electrical system.
3. Evaluating Option (b) Isolator: An isolator is a mechanical switch used to isolate a part of the circuit for maintenance. It is operated manually and must only be operated under 'no-load' conditions; it cannot break a fault current.
4. Evaluating Option (c) Relay: A relay is a sensing device. It detects the fault condition and sends a signal (trip command) to the circuit breaker. While it is part of the protection system, the relay itself does not 'break' the high-power circuit; it only triggers the breaker to do so.
5. Evaluating Option (d) Capacitor: A capacitor is a passive component used to store electrical energy in an electric field. It has no function in automatically breaking a circuit during a fault.
Conclusion: The Circuit Breaker is the actual device that performs the physical action of breaking the circuit automatically.
Which device is used to measure the current in transmission lines?
A)
Energy meter
B)
Potential Transformer
C)
Wattmeter
D)
Current Transformer
In high-voltage transmission lines, the current is too high to be measured directly by standard ammeters. A Current Transformer (CT) is an instrument transformer used to step down the high primary current to a lower, standardized value (typically 1A or 5A) that can be safely measured by an ammeter.
Why other options are incorrect:
- a. Energy meter: Measures the total electrical energy consumed over a period of time (kWh), not the instantaneous current.
- b. Potential Transformer: Used to step down high voltage to a lower level for safe measurement of voltage, not current.
- c. Wattmeter: Measures the active electrical power (kW) in a circuit, which is a product of voltage, current, and power factor.
What happens to the conductivity of a semiconductor when temperature increases?
A)
It decreases
B)
It remains constant
C)
It increases
D)
It becomes zero
In a semiconductor, the valence band is full and the conduction band is empty at absolute zero (0K). As the temperature increases, thermal energy is provided to the electrons in the valence band. This energy allows more electrons to overcome the energy band gap (Eg) and jump from the valence band to the conduction band. This process creates free electrons in the conduction band and holes in the valence band, both of which act as charge carriers. Since conductivity (σ) is proportional to the concentration of charge carriers (n), an increase in temperature leads to an increase in the number of available carriers, thereby increasing the conductivity of the semiconductor. This is the opposite behavior of metals (conductors), where conductivity decreases as temperature increases due to increased lattice vibrations (scattering).
What is the main purpose of trenching in rural sanitation?
A)
Laying pipelines
B)
Disposal of night soil
C)
Foundation laying
D)
Water harvesting
In the context of rural sanitation, 'trenching' specifically refers to the construction of trench latrines or disposal trenches. These are used for the safe disposal of night soil (human excreta) in areas where permanent sewerage systems are unavailable or during emergency/temporary camp setups. The process involves digging a trench, filling it with layers of soil and organic matter (or lime), and covering it to prevent odors and the spread of diseases.
Why other options are incorrect:
- a. Laying pipelines: While pipelines are laid in trenches, this is a general civil engineering activity (pipelaying) rather than a specific 'rural sanitation' method for waste management.
- c. Foundation laying: This is a structural engineering process for buildings, not a sanitation practice.
- d. Water harvesting: This involves pits, ponds, or recharge wells, but the specific term 'trenching' in a sanitation exam context almost always refers to the disposal of waste/night soil.
A pump set draws more current than rated during operation. The most likely electrical cause is
A)
High voltage supply
B)
Proper earthing
C)
Motor overloading
D)
Low winding temperature
Step-by-step reasoning:
1. Understanding Current Draw: In an electric motor, the current drawn is directly proportional to the mechanical load (torque) applied to the shaft.
2. Analyzing Motor Overloading: When a pump set is overloaded (e.g., due to a jammed impeller, high fluid viscosity, or pumping beyond rated capacity), the motor must produce more torque to maintain its speed. To produce this additional torque, the motor draws more current from the power supply, often exceeding its rated current (Full Load Amps).
3. Evaluating other options:
- (a) High voltage supply: Generally, an increase in voltage does not lead to a significant increase in current for an induction motor at a constant load; in some cases, it may slightly decrease current or cause saturation, but it is not the 'most likely' cause of overcurrent compared to overloading.
- (b) Proper earthing: Earthing is a safety mechanism to prevent electric shock and does not affect the operational current draw of the motor under normal conditions.
- (d) Low winding temperature: Lower temperatures typically result in lower resistance in the windings. While this might slightly affect current, it would not cause a motor to draw 'more than rated' current during operation; in fact, overheating is usually a result of high current, not the cause of it.
What is the main purpose of using a starter for motors in a pumping station?
A)
To reduce water flow
B)
To cool the motor
C)
To limit starting current
D)
To increase voltage
When an electric motor (especially an induction motor used in pumping stations) is started directly from the mains, it draws a very high initial current, often 5 to 7 times its rated full-load current. This is because the motor starts from a standstill (zero speed), meaning there is no back-EMF to oppose the supply voltage. This high 'inrush current' can cause voltage dips in the power system, damage the motor windings due to overheating, and put excessive mechanical stress on the pump couplings. A motor starter (such as a Star-Delta starter or an Auto-transformer starter) is used to reduce the starting voltage applied to the motor, thereby limiting the starting current to a safe level.
Analysis of other options:
- (a) To reduce water flow: Water flow is controlled by valves or Variable Frequency Drives (VFDs), not by the starter.
- (b) To cool the motor: Cooling is handled by fans or cooling jackets; starters do not provide cooling.
- (d) To increase voltage: Starters are designed to either maintain or temporarily reduce voltage to protect the motor; they are not used to increase voltage.
The slope of an open channel affects:
A)
Width of pipe
B)
Flow velocity
C)
Temperature
D)
Odour level
In open channel hydraulics, the flow is primarily driven by gravity. The slope of the channel (bed slope) provides the gravitational force that overcomes the frictional resistance of the channel walls and bed. According to Manning's Equation (V = (1/n) * R^(2/3) * S^(1/2}), where V is the average velocity, n is the Manning's roughness coefficient, R is the hydraulic radius, and S is the slope of the energy grade line (which is approximately the bed slope for uniform flow), the velocity (V) is directly proportional to the square root of the slope (S). Therefore, increasing the slope increases the flow velocity.
Why other options are incorrect:
- a. Width of pipe: The width is a geometric design parameter determined by the required discharge capacity, not by the slope itself.
- c. Temperature: Temperature is a thermodynamic property of the fluid and is not affected by the physical slope of the channel.
- d. Odour level: Odour is related to the chemical composition and biological activity (e.g., anaerobic conditions) of the water, not the slope of the channel.
A transformer’s breather shows pink silica gel during inspection. What does this indicate?
A)
Silica gel is functioning normally
B)
Oil level is higher than normal
C)
Silica gel has absorbed moisture
D)
Transformer is running at full load
A transformer breather contains silica gel, which acts as a desiccant to remove moisture from the air entering the conservator tank as the oil expands and contracts. Fresh, dry silica gel is typically blue in color. As it absorbs moisture from the air, a chemical reaction occurs that changes its color to pink. Therefore, when the silica gel turns pink, it indicates that the gel has become saturated with moisture and has lost its effectiveness, signaling that it needs to be replaced or regenerated (dried).
Analysis of other options:
- Option (a) is incorrect because blue is the color for normal, dry functioning; pink indicates saturation.
- Option (b) is incorrect because the color of the silica gel is independent of the oil level in the tank.
- Option (d) is incorrect because while load affects oil temperature and expansion/contraction rates, the color change specifically tracks moisture absorption, not the electrical load of the transformer.
During inspection, a large motor is found running with a power factor of 0.65 lagging. What is the likely effect on the electrical system?
A)
Lower water pressure
B)
Higher energy losses
C)
Reduced cable length
D)
Faster motor speed
Step-by-step reasoning: 1. Power Factor (PF) is the ratio of Real Power (kW) to Apparent Power (kVA). A PF of 0.65 lagging is considered low. 2. For a given real power load, a lower power factor requires a higher current (I) to be drawn from the source (since P = V * I * PF * cos(phi)). 3. Electrical energy losses in cables and transformers are calculated using the formula P_loss = I²R. 4. Because the current (I) increases when the power factor decreases, the I²R losses (copper losses) increase quadratically. 5. Therefore, a low power factor leads to higher energy losses in the distribution system.
Analysis of other options:
- (a) Lower water pressure: This is a mechanical result of pump performance, not a direct electrical effect of the power factor.
- (c) Reduced cable length: Cable length is a physical installation parameter and is not affected by the operational power factor of a motor.
- (d) Faster motor speed: Motor speed is primarily determined by frequency and slip (for induction motors), not by the power factor.
The process of separating biodegradable and non-biodegradable waste is called:
A)
Disposal
B)
Segregation
C)
Collection
D)
Treatment
The process of separating waste into different categories—such as biodegradable (organic) and non-biodegradable (plastics, metals, glass)—at the source or at a processing facility is known as 'Segregation'. This is a critical step in waste management as it allows for efficient recycling and composting.
Why other options are incorrect:
- a. Disposal: This is the final stage of waste management where waste is placed in a landfill or incinerated.
- c. Collection: This refers to the gathering of waste from various points and transporting it to a transfer station or disposal site.
- d. Treatment: This involves the physical, chemical, or biological processing of waste to reduce its toxicity or volume (e.g., composting or anaerobic digestion) after it has been segregated.
The most economical channel section for open flow is:
A)
Semi-circular
B)
Circular
C)
Rectangular
D)
Trapezoidal
In open channel hydraulics, the 'most economical section' is defined as the cross-section that provides the maximum discharge (Q) for a given cross-sectional area (A), slope (S), and roughness coefficient (n). According to Manning's equation, discharge is maximized when the wetted perimeter (P) is minimized, as this reduces the frictional resistance between the fluid and the channel boundaries. Among all possible geometric shapes, a circle has the smallest perimeter for a given area. Therefore, for an open channel (where the top is open to the atmosphere), a semi-circular section provides the minimum wetted perimeter for a given area, making it the most hydraulically efficient or economical section.
Comparison of other options:
- Rectangular: Economical when the width is twice the depth, but still has a larger wetted perimeter than a semi-circle.
- Trapezoidal: The most economical trapezoidal section is half of a hexagon, which is more efficient than a rectangle but less so than a semi-circle.
- Circular: A full circle is a closed conduit (pipe), not an open channel flow section.
The starter which primarily uses power electronics to control voltage during motor start is
A)
Soft starter
B)
DOL
C)
Star – Delta starter
D)
Auto-transformer
Step-by-step reasoning:
1. **Analysis of the Question**: The key phrase is 'primarily uses power electronics to control voltage'. This indicates a need for a starter that can dynamically adjust the voltage applied to the motor during the startup phase.
2. **Evaluating Option (a) Soft Starter**: A soft starter uses power electronic components, specifically Thyristors (SCRs - Silicon Controlled Rectifiers), to gradually increase the voltage supplied to the motor. By controlling the firing angle of these thyristors, it can smoothly ramp up the voltage from a low value to full line voltage, reducing inrush current and mechanical stress. This perfectly matches the question's criteria.
3. **Evaluating Option (b) DOL (Direct-On-Line)**: A DOL starter connects the motor directly to the full supply voltage using a contactor. It involves no voltage control or power electronics for voltage regulation; it is a simple switch.
4. **Evaluating Option (c) Star-Delta Starter**: This is a mechanical/electromagnetic switching method. It starts the motor in 'Star' configuration (reducing voltage to 1/√3 of the line voltage) and then switches to 'Delta'. It uses contactors and timers, not power electronics for continuous voltage control.
5. **Evaluating Option (d) Auto-transformer**: This uses a transformer with taps to provide a reduced voltage during start. It is a passive magnetic component, not a power electronic device.
Conclusion: Only the soft starter utilizes power electronics to control the voltage during the starting sequence.
What should be checked regularly to maintain lead-acid batteries in good condition?
A)
Cable colour
B)
Charger fan speed
C)
Size of terminals
D)
Electrolyte level
Lead-acid batteries contain an electrolyte consisting of sulfuric acid and water. During the charging and discharging process, water can be lost due to evaporation or electrolysis (gassing), especially in vented batteries. If the electrolyte level drops and the lead plates are exposed to air, it can lead to permanent damage (sulfation) and a decrease in battery capacity. Therefore, checking and topping up the electrolyte level with distilled water is a critical part of regular maintenance.
Why other options are incorrect:
- a. Cable colour: The colour of the cables is for identification (e.g., red for positive, black for negative) and does not affect the chemical or electrical health of the battery.
- b. Charger fan speed: While charger cooling is important for the charger's longevity, it is not a maintenance check for the battery itself.
- c. Size of terminals: Terminal size is a fixed physical characteristic determined during manufacturing and does not change or require regular checking for maintenance.
The key reason for conducting a water supply survey is to:
A)
Increase groundwater level
B)
Assess rainfall patterns
C)
Improve road network
D)
Plan intake and reservoir location
A water supply survey is a comprehensive preliminary investigation conducted to gather data necessary for the design and implementation of a water supply system. The primary objectives of such a survey include determining the current and future water demand, identifying available water sources, and analyzing the topography of the area. This data is critical for the strategic planning of infrastructure, specifically the location of the intake (where water is drawn from the source) and the reservoir/service reservoirs (where water is stored for distribution), to ensure gravity flow where possible and minimize pumping costs.
Why other options are incorrect:
- Option (a): Increasing groundwater levels is a result of rainwater harvesting or groundwater recharge projects, not a reason for conducting a survey.
- Option (b): While rainfall patterns are studied during a survey to estimate water yield, the 'key reason' for the overall survey is the planning of the supply system, not just assessing rainfall.
- Option (c): Improving road networks is the domain of transportation or civil infrastructure engineering, not water supply engineering.
Which structure is built for retaining soil?
A)
Septic tank
B)
Soak pit
C)
Infiltration gallery
D)
Retaining wall
A retaining wall is a structure specifically designed to resist the lateral pressure of soil, preventing it from sliding or collapsing. It is commonly used in areas where there is a steep change in ground elevation, such as along roadsides, basements, or bridge abutments.
Analysis of other options:
- a. Septic tank: A watertight container used for the primary treatment of sewage.
- b. Soak pit: A covered pit that allows wastewater to slowly soak into the ground.
- c. Infiltration gallery: A horizontal structure used to collect groundwater from a sandy or gravelly aquifer.
Therefore, only the retaining wall is built for the purpose of retaining soil.
Which material is commonly used for conductors in machine windings?
A)
Rubber
B)
Copper
C)
Lead
D)
Brass
In electrical machines (such as motors, generators, and transformers), the windings require a material with high electrical conductivity to minimize power loss due to heating (I²R losses) and to maximize efficiency.
1. **Copper (Option b):** It is the most commonly used material for windings because it has one of the highest electrical conductivity values among all metals (second only to silver, which is too expensive for industrial use). It also possesses good ductility and thermal conductivity.
2. **Rubber (Option a):** Rubber is an insulator, not a conductor. It is used for insulation of wires, not for the conductor itself.
3. **Lead (Option c):** Lead has very poor electrical conductivity compared to copper and is too soft and heavy for use in machine windings.
4. **Brass (Option d):** Brass is an alloy of copper and zinc. While it is conductive, its conductivity is significantly lower than that of pure copper, leading to higher energy losses.