ICT, Communication Skills, and Entrepreneurship Education Exam, Nov 2024

ICT, Communication Skills, and Entrepreneurship Education Exam, Nov 2024

SECTION A: INFORMATION COMMUNICATION TECHNOLOGY

1(a) Distinguish between analog and digital computers.
Answer: Analog computers process continuous data, often used for measuring physical quantities like temperature. Digital computers process discrete data using binary (0s and 1s), commonly used for calculations and data storage.

(b) Explain the following terms in relation to computer software:
(i) Compatibility
Answer: Compatibility refers to the ability of software to run on different hardware or operating systems without requiring modification.

(ii) Portability
Answer: Portability is the ease with which software can be transferred from one computing environment to another with minimal modification.

(c) List two functional units of the central processing unit of a computer.
Answer:

1. Arithmetic Logic Unit (ALU)
2. Control Unit (CU)

2 (a) State two options that will appear when a computer user presses the following combination of keys on a computer running on a Windows operating system; Ctrl + Alt + Del.
Answer:

1. Task Manager
2. Lock Screen

(b) Describe two ways in which an airline company may use ICT to enhance its operations.
Answer:

1. Online Booking System – Passengers can book tickets and check flight availability online.
2. Customer Relationship Management (CRM) – Airlines use ICT to handle customer inquiries, complaints, and loyalty programs.

(c) Explain each of the following features found in a presentation package:
(i) Animation
Answer: Animation refers to the movement effects applied to text, images, or objects in a slide to enhance engagement.

(ii) Slide Transition
Answer: Slide transition is the visual effect applied when moving from one slide to another in a presentation.

3 (a) A school bursar has the following fields in a table in his database: name_of_birth, admission_number, fees_paid, has_scholarship.
(i) Identify the field that is most appropriate for a primary key.
Answer: Admission_number

(ii) State the data type that is appropriate for each of the fields.
Answer:

• Name_of_birth: Text
• Admission_number: Integer
• Fees_paid: Currency
• Has_scholarship: Boolean

(b) Distinguish between a pasteboard and the printable area in desktop publishing.
Answer: A pasteboard is the workspace around a document where elements can be temporarily placed, while the printable area is the section of the document that can be printed within the printer’s margins.

4(a) Table 1 was created using a word processor.
Identify six formatting features applied on the table.
Answer:

1. Bold text
2. Center alignment
3. Borders
4. Shading
5. Merged cells
6. Different font sizes

(b) Explain each of the following terms as used in data security:
(i) Data Encryption
Answer: Data encryption is the process of converting data into a coded format to prevent unauthorized access.

(ii) Audit Trail
Answer: An audit trail is a record of system activities that helps track changes and access to data for security purposes.

5(b) Describe each of the following network topologies:

(i) Bus topology
Answer: A network setup where all devices share a single communication line or backbone.

(ii) Star topology
Answer: A network setup where all devices are connected to a central hub or switch.

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SECTION B: COMMUNICATION SKILLS

6 (a) State three sender-oriented factors that may contribute to communication breakdown during an oral conversation.
Answer:

1. Poor articulation
2. Use of jargon
3. Lack of clarity

(b) Outline three consequences of poor public relations in an engineering firm.
Answer:

1. Loss of customer trust
2. Reduced business opportunities
3. Negative brand image

(c) Highlight three criteria that a paragraph should meet to be considered well developed.
Answer:

1. Unity
2. Coherence
3. Adequate supporting details

(d) Identify three types of information that should be contained in the title page of an investigative report.
Answer:

1. Title of the report
2. Author’s name
3. Date of submission

(e) State three ways in which the management of an organisation may motivate the employees through effective communication.
Answer:

1. Open-door policy
2. Regular feedback
3. Recognition of achievements

(f) Rewrite the following paragraph punctuating it correctly:
Answer: One day, walking together up a hill, I said to Magdaline, “Do you not desire to be in your own country again?” “Yes,” she said.

7 (a) Highlight four ways in which courtesy may be demonstrated in letter writing.
Answer:

1. Using polite language
2. Proper salutation
3. Acknowledging the recipient’s concerns
4. Closing the letter respectfully

(b) Explain three benefits that an individual may derive from intrapersonal communication.
Answer:

1. Self-reflection
2. Decision-making improvement
3. Emotional regulation

8 (a) The agenda of a meeting makes significant contributions to the success of a meeting. State four such contributions.
Answer:

1. Keeps discussions focused
2. Saves time
3. Ensures all topics are covered
4. Assigns responsibilities

(b) Outline three differences between upwards communication and horizontal communication.
Answer:

1. Upward communication flows from subordinates to superiors, while horizontal communication flows among peers.
2. Upward communication is formal, while horizontal can be informal.
3. Upward communication reports problems, while horizontal facilitates teamwork.

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SECTION C: ENTREPRENEURSHIP EDUCATION

9 (a) State four advantages of salaried employment.
Answer:

1. Job security
2. Fixed income
3. Employee benefits
4. Career growth opportunities

(b) The business description section of a business plan contains certain types of information. Outline six such information.
Answer:

1. Business name
2. Location
3. Mission statement
4. Business objectives
5. Products/services
6. Target market

10. (a) List four personal traits of a successful entrepreneur.

Answer:

1. Risk-taking – Willing to take calculated risks for business growth.
2. Creativity – Ability to develop innovative solutions and business ideas.
3. Persistence – Determination to overcome challenges and failures.
4. Self-discipline – Ability to stay focused and committed to business goals.

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(b) Explain three guidelines that an entrepreneur should follow when using the brainstorming technique to generate a business idea.

Answer:

1. Encourage free thinking – All ideas should be welcomed without criticism to foster creativity.
2. Quantity over quality – The focus should be on generating as many ideas as possible before refining them.
3. Build on others’ ideas – Participants should expand on or combine ideas to improve them.

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11. (a) Identify four internal sources of finance available to an entrepreneur.

Answer:

1. Personal savings – Money set aside by the entrepreneur.
2. Retained earnings – Profits reinvested into the business instead of being withdrawn.
3. Sale of assets – Selling business or personal property to generate funds.
4. Contributions from family and friends – Financial support from close associates.

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(b) Explain three ways in which a business enterprise may demonstrate its responsibility to its employees.

Answer:

1. Providing fair wages and benefits – Ensuring employees receive competitive salaries and benefits.
2. Ensuring a safe work environment – Complying with safety standards to protect workers.
3. Offering career growth opportunities – Providing training and promotions to enhance employee skills.

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12 (a) Certain factors may account for the failure of a new business. Highlight four such factors.

Answer:

1. Poor financial management – Misuse or misallocation of funds leading to cash flow problems.
2. Lack of market research – Failure to understand customer needs and competition.
3. Inadequate business planning – Absence of a clear strategy for operations and growth.
4. Poor customer service – Loss of customers due to bad service and negative reputation.

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 (b) Explain three social factors that may promote entrepreneurial development in a country.

Answer:

1. Education and training – Access to business knowledge and skills through formal and informal education.
2. Supportive government policies – Favorable regulations, incentives, and grants for entrepreneurs.
3. Cultural acceptance of entrepreneurship – A society that encourages innovation and self-employment.

ELECTRICAL MEASUREMENTS AND ANALOGUE ELECTRONICS I NOV 2024

SECTION A: ELECTRICAL MEASUREMENTS

 

1 (a) i. Define ‘measurement’ with respect to physical quantities.

Answer:
Measurement is the process of determining the value of a physical quantity by comparing it with a standard unit.

i. State three basic units of measurement.

Answer:

1. Meter (m) – Unit of length.
2. Kilogram (kg) – Unit of mass.
3. Second (s) – Unit of time.

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2(a) Define maintainability, reliability, and redundancy with respect to system reliability.

Answer:

1. Maintainability: The ease with which a system can be repaired or maintained.
2. Reliability: The probability of a system performing correctly over a given time.
3. Redundancy: The inclusion of extra components to improve system reliability.

(b) Distinguish between ‘random’ and ‘partial’ failures.

Answer:

• Random Failure: Unpredictable failures due to sudden component breakdown.
• Partial Failure: When a system operates below optimal performance but is still functional.

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3(a) State five preventive maintenance tasks performed on electrical machines.

Answer:

1. Lubrication of moving parts.
2. Cleaning of dust and dirt.
3. Checking and tightening electrical connections.
4. Inspecting insulation for damage.
5. Testing and calibrating protection devices.

5(b) Describe the input-output method of fault finding in electrical systems with a block diagram.

Answer:

• The input-output method involves checking whether an expected output is received when an input is applied.
• If the output is incorrect, different sections of the circuit are tested step by step to locate the faulty component.

 

5(a) Outline the procedure for measuring resistance using a digital multimeter.

Answer:

1. Set the multimeter to the resistance (Ω) mode.
2. Disconnect the component from the circuit.
3. Connect the multimeter probes across the resistor.
4. Read the displayed resistance value.

(c) State three advantages of digital multimeters over analogue multimeters.

Answer:

1. Higher accuracy and precision.
2. Easier to read due to digital display.
3. Lower power consumption and more durable.

SECTION B: ANALOGUE ELECTRONICS I

6(a) Distinguish between ‘energy level’ and ‘orbital’ with respect to atoms.

Answer:

• Energy Level: A discrete amount of energy that an electron in an atom can possess. Electrons can move between energy levels by absorbing or emitting energy.
• Orbital: A specific region in an atom where an electron is most likely to be found. Orbitals have different shapes (s, p, d, f) and orientations.

(a) Explain the principle of thermionic emission.

Answer:
Thermionic emission is the process where electrons are emitted from a heated metal surface. When a metal is heated to a high temperature, some electrons gain enough energy to overcome the work function and escape from the surface, creating a flow of electrons that can be used in vacuum tubes and electron guns.

 

7 (d) State two areas of applications of transistors and two merits of BJTs.

Answer:

1. Applications:
   • Signal amplification (used in audio amplifiers).
   • Switching (used in logic circuits and microprocessors).
2. Merits of BJTs:
   • High gain and fast switching speeds.
   • Can operate at high current levels compared to FETs.

 

SECTION A: PHYSICAL SCIENCE

1(a) (i) Define radioactive decay.

Radioactive decay is the spontaneous disintegration of an unstable atomic nucleus into a more stable nucleus by emitting radiation, such as alpha, beta, or gamma rays.

 (ii) Describe each of the following ionizing radiations:
(I) Alpha radiation – Consists of two protons and two neutrons (a helium nucleus). It has low penetration power but is highly ionizing. It can be stopped by a sheet of paper.
(II) Beta radiation – Consists of fast-moving electrons or positrons. It has moderate penetration power and can be stopped by aluminum foil.
(III) Gamma radiation – Electromagnetic waves with high energy. It has high penetration power and requires thick lead or concrete to stop it.

(b) An object of mass 0.25 kg is attached to the lowest end of a vertically hanging spring and produces an extension of 75 mm. If the object is then pulled down by 20 mm and set into a vertical simple harmonic motion, determine the:
(i) Spring constant
Using Hooke’s Law:

$$F=kx$$

Where:

• $F=mg=0.25\times 9.81=2.4525$ N
• $x=75$ mm = 0.075 m

k=Fx=2.45250.075=32.7 N/mk = frac{F}{x} = frac{2.4525}{0.075} = 32.7 text{ N/m}k=xF​=0.0752.4525​=32.7 N/m

(ii) Periodic time

T=2πmkT = 2pi sqrt{frac{m}{k}}T=2πkm​​ T=2π0.2532.7T = 2pi sqrt{frac{0.25}{32.7}}T=2π32.70.25​​ $$T\approx 0.55\text{ seconds}$$

(c) Explain the term ‘damping’ with reference to vibration.
Damping is the gradual reduction of the amplitude of an oscillating system due to the loss of energy, usually as heat, from friction or resistance.

(d) (i) Differentiate between anions and cations with reference to electrolysis.

• Anions are negatively charged ions that migrate to the anode (positive electrode) during electrolysis.
• Cations are positively charged ions that migrate to the cathode (negative electrode) during electrolysis.

(d) (ii) State three areas of application of electrolysis.

1. Electroplating metals
2. Extraction of metals (e.g., aluminum extraction from bauxite)
3. Purification of metals (e.g., refining copper)

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 2(a) (i) State three characteristics of plane progressive waves.

1. Particles vibrate in phase with each other.
2. The wave moves in a uniform direction.
3. Energy is transferred through the medium without the medium itself moving.

(a) (ii) A simple harmonic wave traveling in the positive x direction is given by the equation:

$$y=3\sin (157t-0.42x)\text{ cm}$$

Determine the:

(I) Wavelength
From the equation, the wave number $k=0.42$.

λ=2πk=2π0.42≈14.96 cmlambda = frac{2pi}{k} = frac{2pi}{0.42} approx 14.96 text{ cm}λ=k2π​=0.422π​≈14.96 cm

(II) Frequency
From the equation, angular frequency $\omega =157$.

f=ω2π=1572π≈25 Hzf = frac{omega}{2pi} = frac{157}{2pi} approx 25 text{ Hz}f=2πω​=2π157​≈25 Hz

(III) Speed of the wave

$$v=f\lambda =(25)(14.96)=374\text{ cm/s}$$

(b) (i) Explain ‘latent heat of fusion’.
Latent heat of fusion is the amount of heat required to convert a solid into a liquid at its melting point without changing its temperature.

(b) (ii) A 1.5 kg of dry ice at 0°C melts into water. The specific latent heat of fusion of ice is 33,600 J/kg. Determine the heat absorbed.

$$Q=mL$$ $$Q=(1.5)(33,600)=50,400\text{ J}$$

(c) (i) Describe isomers with reference to hydrocarbons.
Isomers are compounds that have the same molecular formula but different structural arrangements, leading to different physical and chemical properties.

(c) (ii) State two types of isomerism.

1. Structural isomerism
2. Stereoisomerism

(d) The condensed structural formula of propene is given as CH₂=CHCH₃. Determine its molecular mass.

$$M=(2\times 12)+(4\times 1)+(1\times 12)+(3\times 1)$$ $$=42\text{ g/mol}$$

SECTION B: MECHANICAL SCIENCE

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3(a) (i) State two forms of potential energy.

1. Gravitational potential energy – Energy stored in an object due to its position above the ground.
2. Elastic potential energy – Energy stored in a stretched or compressed elastic material, such as a spring or rubber band.

(c) (i) State the principle of conservation of momentum.
The total momentum of an isolated system remains constant before and after a collision, provided no external forces act on it.

(ii) State two factors that affect the momentum of a body.

1. Mass of the body
2. Velocity of the body

(d) (i) Define the term angular displacement with reference to dynamic motion.
Angular displacement is the angle through which a rotating object moves, measured in radians.

  (ii) Differentiate between ‘angular’ and ‘linear’ velocities citing the SI unit in each case.

• Angular velocity ($\omega$) – Rate of change of angular displacement (unit: rad/s).
• Linear velocity ($v$) – Rate of change of linear displacement (unit: m/s).

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4(a) (i) Differentiate between brittleness and malleability with reference to properties of materials.

• Brittleness – The tendency of a material to break or shatter without significant deformation (e.g., glass).
• Malleability – The ability of a material to be hammered or rolled into thin sheets without breaking (e.g., aluminum).

4(b) (i) State Archimedes’ principle.

A body submerged in a fluid experiences an upward buoyant force equal to the weight of the displaced fluid.

 

(c) (i) Define mechanical power transmission.
The process of transferring mechanical energy from one point to another using gears, belts, chains, or shafts.

(c) (ii) State five types of mechanical coupling devices.

1. Rigid couplings
2. Flexible couplings
3. Fluid couplings
4. Gear couplings
5. Universal joints

SECTION C: ELECTRICAL ENGINEERING PRINCIPLES

5(a) State three basic SI unit quantities.

1. Length – Meter (m)
2. Mass – Kilogram (kg)
3. Time – Second (s)

(b) Outline two differences between primary and secondary cells.

Primary Cell	Secondary Cell
Cannot be recharged	Can be recharged
Used once and discarded	Used multiple times
Example: Dry cell	Example: Lead-acid battery

 

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Question 6

(a) State two instruments used to measure continuity in a circuit.

1. Multimeter
2. Continuity tester

7(a) Define the following terms with reference to magnetism:

(i) Magnetic field lines
These are imaginary lines that represent the direction and strength of a magnetic field. They emerge from the north pole and enter the south pole of a magnet.

(ii) Magnetic flux
Magnetic flux ($\Phi$) is the total number of magnetic field lines passing through a surface. It is measured in Weber (Wb).

(iii) Reluctance
Reluctance ($R$) is the opposition to the flow of magnetic flux in a magnetic circuit, similar to electrical resistance in an electrical circuit. It is measured in Ampere-Turns per Weber (A-t/Wb).

(d) (i) Name two types of capacitors.

1. Electrolytic capacitor
2. Ceramic capacitor

 

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8 (a) State the relationship between current and voltage in each of the following pure elements when connected to an a.c supply:

(i) Resistor
Voltage and current are in phase.

(ii) Capacitor
Current leads voltage by 90°.

(iii) Inductor
Voltage leads current by 90°.

SECTION A: MATERIALS, PROCESSES AND WORKSHOP TECHNOLOGY

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1(a) State three safety precautions under each of the following:

Electricity:

1. Always switch off the power supply before working on electrical circuits.
2. Use insulated tools and wear rubber gloves while handling live wires.
3. Avoid overloading electrical sockets to prevent short circuits and fire hazards.

Machine tools:

1. Wear safety goggles to protect the eyes from flying metal chips.
2. Ensure workpieces are firmly clamped before machining.
3. Never leave running machines unattended.

Hand tools:

1. Always use the right tool for the right job.
2. Keep cutting tools sharp and in good condition.
3. Store tools properly after use to prevent accidents.

(b) State the meaning of the following warning signs and safety colours:

• Circle: Represents a mandatory instruction (e.g., “Wear safety goggles”).
• Triangle: Indicates a warning (e.g., “Caution: Hot surface”).
• Rectangle: Represents information or guidance (e.g., “Fire Exit”).
• Red: Indicates danger or prohibition (e.g., “Stop” or “Fire Equipment”).
• Green: Denotes safety (e.g., “First Aid” or “Safe Exit”).

(c) Outline the procedure for dressing a cut in the workshop:

1. Wash hands and wear disposable gloves.
2. Clean the wound using antiseptic and a clean cloth.
3. Apply pressure to stop bleeding if necessary.
4. Cover the wound with a sterile bandage.
5. Seek medical attention if the cut is deep.

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2(a) Define the following properties of engineering materials, giving one example in each case:

1. Magnetism: The ability of a material to attract iron or steel. Example: Iron.
2. Brittleness: The tendency of a material to break or shatter without significant deformation. Example: Glass.
3. Elasticity: The ability of a material to return to its original shape after deformation. Example: Rubber.

(c) List four types of metal finishing and decorative processes.

1. Electroplating
2. Anodizing
3. Painting
4. Polishing

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3(a) Outline the following for the engineer’s square:

Uses:

1. Checking the squareness of metal workpieces.
2. Marking perpendicular lines.

Main parts:

1. Blade
2. Stock

Care and maintenance:

1. Store in a dry place to prevent rust.
2. Avoid dropping to maintain accuracy.

 

(c) Illustrate two methods of measuring the width of a flat workpiece from a datum edge.

1. Using a vernier caliper.
2. Using a steel rule and surface gauge.

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 4(a) List four tools and equipment used in the oxy-acetylene welding process.

1. Oxygen cylinder
2. Acetylene cylinder
3. Welding torch
4. Pressure regulators

(b) State two welding techniques used in gas welding.

1. Forehand welding
2. Backhand welding

(c) Explain the principle of operation of a centre lathe.
The centre lathe operates by rotating a workpiece against a cutting tool, allowing for operations such as turning, facing, drilling, and threading.

(d) List four parts of a lathe machine.

1. Headstock
2. Tailstock
3. Carriage
4. Bed

(e) Outline three safety precautions to be observed while operating a lathe machine.

1. Remove loose clothing and wear safety goggles.
2. Ensure the chuck key is removed before starting.
3. Do not leave the machine unattended while running.

 

SECTION A: ELECTRICAL INSTALLATION TECHNOLOGY

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1(a) Define the following terms:

1. Wiring system: A method of installing electrical wiring and associated accessories within a building or structure to provide electrical power safely and efficiently.
2. Diversity factor: The ratio of the sum of the individual maximum demands of various loads in a system to the maximum demand of the entire system. It helps in designing electrical installations to avoid over-sizing.

(b) Describe three factors to be considered when choosing a wiring system for a particular installation.

1. Nature of the environment: Factors like humidity, temperature, and exposure to chemicals affect the choice of wiring system.
2. Load requirement: The type and amount of electrical load determine the wire size and insulation requirements.
3. Aesthetics and accessibility: Concealed wiring is preferred for aesthetics, while exposed wiring allows for easier maintenance.

(c) List two types of wiring accessories and for each case, state its function.

1. Switch: Used to control the flow of electricity to a device.
2. Socket outlet: Provides a connection point for plugging in electrical appliances.

(d) (i) Explain the “looping in” method as used in electrical installation.
The “looping in” method involves connecting electrical outlets or switches by looping the live wire from one point to another without using joint boxes.

(ii) State three advantages of the “looping in” method.

1. Reduces the number of joint boxes, making the system neater.
2. Minimizes voltage drop and electrical losses.
3. Simplifies fault detection and maintenance.

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2(a) Outline four safety measures observed when working with electrical equipment.

1. Always switch off the power supply before performing maintenance.
2. Use insulated tools to prevent electric shocks.
3. Wear personal protective equipment (PPE) such as gloves and safety goggles.
4. Avoid working on live circuits unless absolutely necessary.

(b) State four classes of fire citing an example in each case.

1. Class A: Fires involving solid materials (e.g., wood, paper).
2. Class B: Fires involving flammable liquids (e.g., petrol, oil).
3. Class C: Fires involving gases (e.g., propane, methane).
4. Class D: Fires involving metals (e.g., magnesium, aluminum).

 

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3(a) Describe the following terms as applied in earthing system:

1. Solidly earthed: A system where the neutral conductor is directly connected to the ground without resistance to minimize voltage fluctuations.
2. Earthed: A system where an electrical installation is connected to the ground to provide safety from electric shocks.

 

(c) Distinguish between a class P and a class R fuse.

1. Class P fuse: Used in power circuits, provides high-breaking capacity.
2. Class R fuse: Used for industrial applications with high short-circuit currents, offering better protection against overcurrents.

(d) (i) Define the term “structured cabling.”
Structured cabling is a standardized approach to installing and managing network cables in a building or data center to support communication systems efficiently.

(ii) Describe the entrance facilities of structured cabling.
Entrance facilities refer to the point where external network cables (e.g., fiber optic or copper) enter a building and connect to the internal structured cabling system. It includes grounding, conduit protection, and network demarcation points.

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4(b) (i) Explain a fire alarm system.

A fire alarm system is an electronic system that detects smoke, heat, or flames and alerts occupants through alarms or notifications.

(ii) State two purposes of the fire alarm system.

1. To warn building occupants of a fire hazard.
2. To trigger automatic fire suppression systems (e.g., sprinklers).

(c) Outline two IEE regulation requirements of a bell transformer.

1. The transformer should be double insulated for safety.
2. The secondary voltage should not exceed 24V AC to prevent electric shocks.

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5 (a) Outline three contents of a completion certificate required by Kenya Power Company for a person to be connected to the power supply.

1. Name and license number of the certified electrician who carried out the installation.
2. Test results confirming the installation meets safety standards.
3. A declaration that the installation complies with IEE regulations.

 

(d) (i) List two types of cable joints.

1. Straight joint – used to connect two cables of the same type.
2. T-joint – used to branch one cable into two separate paths.

(ii) State three IEE regulation requirements regarding electrical cable joints.

1. Joints must be mechanically strong and electrically continuous.
2. Joints must be insulated properly to prevent short circuits.
3. Soldered joints should be smooth and free of excess flux to avoid corrosion.

SECTION B: SOLAR INSTALLATION TECHNOLOGY

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 6(a) Define the following terms as applied in solar energy:

1. Solar constant: The amount of solar energy received per unit area at the Earth’s upper atmosphere, approximately 1.366 kW/m².
2. Irradiance: The power of solar radiation per unit area, measured in watts per square meter (W/m²).
3. Photovoltaic (PV): The process of converting sunlight directly into electricity using solar cells.

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 7(a) State two:

(i) Advantages of using solar electric energy over diesel generators.

1. No fuel cost: Solar energy is free, whereas generators require expensive fuel.
2. Environmentally friendly: Solar energy does not produce emissions like diesel generators.

(ii) Factors that determine the amount of electrical energy produced by a solar module.

1. Solar panel efficiency: Higher efficiency panels generate more electricity.
2. Sunlight duration and intensity: More sunlight leads to higher energy production.

(b) Distinguish between a mono-crystalline and a poly-crystalline construction of solar cells.

1. Mono-crystalline: Made from a single silicon crystal, higher efficiency but more expensive.
2. Poly-crystalline: Made from multiple silicon fragments, lower efficiency but cheaper.

(d) Outline the procedure of cleaning a solar battery during monthly maintenance.

1. Disconnect the battery from the system.
2. Clean the terminals using a baking soda solution to remove corrosion.
3. Check the electrolyte level and top up with distilled water if needed.
4. Ensure the battery is in a well-ventilated area during charging.
5. Reconnect the battery securely and check for loose connections.

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 8(a) Explain three solar energy conversions citing an example in each case.

1. Photovoltaic conversion: Sunlight is converted into electricity using solar panels. (Example: Solar home systems.)
2. Thermal conversion: Solar energy is converted into heat. (Example: Solar water heaters.)
3. Chemical conversion: Sunlight is used to drive chemical reactions. (Example: Photosynthesis in plants.)

(b) With reference to the I-V curve, explain the following:

1. I_sc (Short-circuit current): The maximum current when voltage is zero (circuit is shorted).
2. V_oc (Open-circuit voltage): The maximum voltage when no current flows (circuit is open).
3. P_max (Maximum power point): The point on the curve where the solar panel delivers the most power.

(c) A domestic house consists of the following loads:

Load	Power (W)	Hours/day	Energy (Wh/day)
18 W fluorescent lamp	18	4	72
60 W fan	60	2	120
75 W refrigerator	75	12	900

(i) Total daily load energy demand:
72 + 120 + 900 = 1,092 Wh/day

(ii) Total daily system energy requirement (30% losses included):
1,092 × 1.3 = 1,419.6 Wh/day

(iii) Number of PV panels required (100W panel, 5 peak sun hours):
1,419.6 ÷ (100 × 5) = 2.84 ≈ 3 panels.

So, at least 3 PV panels are needed to meet the demand.