KSEB Electricity Worker Study Notes 2026 – Free Module-Wise Notes & PDF Download

Preparing for the Kerala PSC Electricity Worker exam? We have attached KSEB Electricity Worker Study Notes 2026 covering all 10 modules of the official syllabus in short, exam-focused points. Each module carries 10 marks, with key concepts, formulas, and comparison tables covering topics from Basic Electricity to Transmission.

 Read the notes below first. Then use the module-wise PDF table to practise with 310 solved questions and answers.

Kerala PSC Electricity Worker Exam 2026 – Key Details

KSEB Electricity Worker Syllabus at a Glance – 10 Modules × 10 Marks

The exam slot is longer than the paper itself. Reach your centre well before 7:00 AM and follow the instructions on your admission ticket. For the official details, see the Kerala PSC notification and the official syllabus PDF.

Need the full topic list? Read our detailed KSEB Electricity Worker syllabus and exam pattern guide.

KSEB Electricity Worker Study Notes PDF – Module-Wise Download

Download the free Q&A PDF for each module. Together they contain 310 questions and answers.

How to Use These KSEB Electricity Worker Study Notes

1. Read one module’s notes and note down the formulas.
2. Practise with that module’s Q&A PDF from the table below.
3. Test yourself with the previous year question papers to see how the questions are framed.

KSEB Electricity Worker Study Notes – Module 1: Basic Electricity

• Atom: The nucleus holds protons (positive) and neutrons (neutral). Electrons (negative) move in shells. Free electrons in the outer shell carry current.
• Basic units: Current in ampere (I = Q/t), voltage in volt, resistance in ohm, power in watt (P = V × I). Energy is measured in kWh, and 1 kWh equals one “unit”.
• Soldering: Solder is a tin-lead alloy, commonly 60/40. Flux cleans oxide and helps the solder flow. Use rosin flux for electrical work, and never acid flux because it corrodes the joint.
• Dry (cold) joint: A dull, grainy joint caused by insufficient heat. It gives poor electrical contact.
• Property of resistance: R = ρL/A, where ρ is the resistivity in ohm-metre.

• Wires vs cables: A wire is a single conductor. A cable has insulated conductors in a common sheath. In SWG (Standard Wire Gauge), a higher number means a thinner wire. Common types are PVC, VIR, TRS/CTS, flexible and armoured cables.

KSEB Electricity Worker Notes – Module 2: Ohm’s Law, Kirchhoff’s Law and Cells

• Ohm’s law: V = IR at constant temperature. Example: 230 V across 46 Ω gives 5 A.
• Kirchhoff’s laws: KCL says the algebraic sum of currents at a junction is zero (conservation of charge). KVL says the algebraic sum of EMFs and voltage drops in a closed loop is zero (conservation of energy).
• Temperature and resistance: Metals increase in resistance as they heat up. Semiconductors, carbon, insulators and electrolytes decrease. Eureka and manganin change very little.
• Chemical effect: Electrolysis splits an electrolyte. The anode is connected to the positive terminal, the cathode to the negative. It is used in electroplating and refining. Faraday’s first law: m = Z I t.
• Laws of resistance: R is proportional to length, inversely proportional to area, and depends on material and temperature. If a wire is stretched to double its length, its resistance becomes four times.
• Cells: Primary cells (dry cell, Leclanché) cannot be recharged. Secondary cells (lead-acid, Ni-Cd, Li-ion) can. A depolariser (MnO₂ in a dry cell) removes hydrogen bubbles.
• Grouping: In series, EMF adds up (nE) and internal resistance is nr. In parallel, EMF stays E, internal resistance is r/n, and current capacity increases.
• Care of a lead-acid battery: Top up only with distilled water. Fully charged specific gravity is about 1.250–1.280, measured with a hydrometer. Keep the terminals clean and greased, and avoid overcharging.
• Buckling: Plates bend because of excess current, short circuit or overheating.
• Sedimentation: Active material shed from the plates collects at the bottom of the cell. It can cause short circuits.

KSEB Electricity Worker Study Notes – Module 3: Magnetism

• Diamagnetic: weakly repelled (copper, bismuth, zinc, silver). Paramagnetic: weakly attracted (aluminium, platinum). Ferromagnetic: strongly attracted (iron, nickel, cobalt), and loses magnetism above the Curie temperature.
• Electromagnetism: A current-carrying conductor produces a magnetic field. Its direction follows the right-hand thumb rule. A soft iron core makes a solenoid much stronger.
• Fleming’s left-hand rule gives the direction of force, so it applies to motors. Fleming’s right-hand rule gives the direction of induced EMF, so it applies to generators.
• Magnetic circuit:

• Faraday’s laws: An EMF is induced when the flux linked with a coil changes, and e = N × dΦ/dt. Lenz’s law: the induced current opposes the cause that produces it.
• Capacitor: C = Q/V, measured in farad. C = εA/d. Types are paper, mica, ceramic and electrolytic (polarised). Uses include filtering, power factor improvement and motor starting. Capacitors in parallel add up; in series 1/C = 1/C₁ + 1/C₂.

KSEB Electricity Worker Notes – Module 4: Alternating Current and Earthing

• AC values: Supply frequency is 50 Hz, and f = 1/T. RMS = 0.707 × peak, average = 0.637 × peak, form factor = 1.11, peak factor = 1.414.
• Supply: Single-phase is 230 V. Three-phase is 415 V between lines. In star, line voltage = 1.732 × phase voltage.
• Why earthing: It protects people from shock and equipment from damage, and it lets the fuse or MCB trip on a fault.
• Pipe earthing: A GI pipe about 38 mm in diameter and 2.5 m long, packed with alternate layers of charcoal and salt. Plate earthing: a 60 cm × 60 cm plate buried about 3 m deep. The earth wire is coloured green.
• Types of wiring: Cleat (temporary), batten, casing and capping, and conduit (best and most widely used). Industries also use armoured cables and trunking.
• Grading of cables: By voltage: 250 V, 660 V and 1100 V (low tension), and 3.3 kV to 33 kV (high tension). By size, in sq mm.
• Current rating: The maximum current a cable can carry continuously. It depends on conductor size, insulation, ambient temperature and how the cable is laid.
• Megger: An insulation resistance tester with a built-in DC generator. Switch off the supply and disconnect the appliances first. Then test phase-to-neutral and each conductor to earth.

KSEB Electricity Worker Study Notes – Module 5: DC Machine

• Parts: Yoke, poles, field winding, armature, commutator and brushes. The commutator converts AC to DC in a generator.
• EMF equation: E = ΦZNP / 60A. A = P for lap winding and A = 2 for wave winding.
• Generators: Separately excited or self-excited (series, shunt, compound). The series field carries the full load current. The shunt field is in parallel with the armature. In a compound generator, cumulative means the fluxes aid each other and differential means they oppose.
• Uses: Series generators for boosters. Shunt generators for lighting and battery charging. Differential compound generators for arc welding.
• DC motor: It works on the Fleming’s left-hand rule. Back EMF: Eb = V − IaRa. A series motor has high starting torque and must never run without load. A shunt motor runs at nearly constant speed.
• Starters: At start, Ist = V/Ra is very large, so a starter adds resistance. A 3-point starter has terminals L, A and F. A 4-point starter adds a terminal N so that the no-volt coil is not affected by field control.
• Speed control: N ∝ Eb/Φ. Field control (rheostat in the field) gives speed above normal. Armature resistance control gives speed below normal. The Ward-Leonard method gives smooth control over a wide range.

KSEB Electricity Worker Notes – Module 6: AC Motors and Starters

• Speed and slip: Ns = 120f/P and slip s = (Ns − N)/Ns. A 4-pole 50 Hz motor has Ns = 1500 rpm.
• Three-phase induction motor: The stator winding creates a rotating magnetic field. The rotor never reaches synchronous speed. Swap any two supply lines to reverse its direction. Squirrel cage rotors are rugged. Slip ring rotors allow external resistance for high starting torque.
• Single-phase motors: These are not self-starting because the field only pulsates. Types are split-phase, capacitor-start, capacitor-start capacitor-run, PSC (ceiling fans) and shaded-pole. A universal motor runs on both AC and DC.
• Starters:

• AC motor panel wiring: Incoming MCCB or fuse, then contactor, then thermal overload relay, then motor. The control circuit uses ON/OFF push buttons and a hold-on contact. The panel body is earthed.
• Phase sequence: The order in which the three phases reach their positive peak (R–Y–B). Reversing any two phases reverses the motor’s rotation. A phase sequence indicator is used to check it.

KSEB Electricity Worker Study Notes – Module 7: Instruments and Transformers

• Types of instruments: Indicating (ammeter), recording and integrating (energy meter).
• Three torques: Deflecting, controlling (spring or gravity) and damping (air, fluid or eddy current). Eddy-current damping is the most effective.
• Instruments: PMMC works on DC only and has a uniform scale. Moving iron works on AC and DC and has a non-uniform scale. A dynamometer type is used as a wattmeter. An ammeter is connected in series and has very low resistance. A voltmeter is connected in parallel and has very high resistance.
• Transformer: It works on mutual induction. E = 4.44 f N Φm. K = N₂/N₁ = V₂/V₁ = I₁/I₂.
• Parallel operation: It needs the same polarity, the same voltage ratio, the same per-unit impedance and, for three-phase, the same phase sequence.
• Cooling: AN, ONAN, ONAF, OFAF and OFWF. Oil acts as an insulator and coolant. The conservator takes up oil expansion. The breather holds silica gel, which is blue when dry and pink when moist.
• Protection: The Buchholz relay sits between the tank and the conservator. Other protection includes overcurrent relays, differential relays and lightning arresters.

KSEB Electricity Worker Notes – Module 8: Illumination and Basic Electronics

• Illumination: Luminous flux is in lumen, intensity in candela, and illumination in lux (lm/m²). Inverse square law: E = I/d². Lambert’s cosine law: E = I cosθ / d².
• Lamps: Incandescent lamps have low efficacy. A fluorescent tube needs a choke and a starter. LEDs have the highest efficacy and longest life. Sodium vapour lamps are used for street lighting.
• Appliances: Nichrome is used for heating elements. An iron has a bimetallic thermostat. Metal-bodied appliances must be earthed.
• Semiconductors: N-type is doped with a pentavalent impurity (electrons are the majority carriers). P-type is doped with a trivalent impurity (holes are the majority carriers). Barrier potential is 0.7 V for silicon and 0.3 V for germanium.
• Diodes: It conducts in forward bias. A Zener diode works in reverse breakdown and is used as a voltage regulator. An LED is forward biased and a photodiode is reverse biased.
• Rectifiers: Half-wave gives Vdc = Vm/π. Full-wave and bridge give Vdc = 2Vm/π. A bridge rectifier uses four diodes and no centre tap.
• Transistor: NPN or PNP. IE = IB + IC and β = IC/IB. The common-emitter configuration is the most used.

KSEB Electricity Worker Study Notes – Module 9: Power Generation

• Sources: Conventional (coal, oil, gas, hydro, nuclear) and non-conventional (solar, wind, tidal, geothermal, biomass). Renewable sources do not run out.
• Thermal: Coal, then boiler, then steam, then turbine, then alternator. The condenser turns exhaust steam into water. Efficiency is roughly 30–40%.
• Hydro: Water flows through the penstock to the turbine. Pelton is for high head, Francis for medium head and Kaplan for low head. P = 9.81 × Q × H × η kW.
• Nuclear: Fission of uranium-235. The moderator slows neutrons, and control rods (cadmium or boron) absorb them.
• Others: A diesel plant is used for standby power. Solar PV converts sunlight to DC. Wind power is proportional to the cube of wind speed.
• Load terms: Load factor = average load / maximum demand. Demand factor = maximum demand / connected load.

KSEB Electricity Worker Notes – Module 10: Transmission

• High-voltage transmission: The same power at higher voltage means less current, so I²R loss falls sharply.
• Voltage levels: Transmission at 132, 220, 400 and 765 kV. Distribution at 11 kV, then 415 V/230 V to consumers.
• Overhead lines: Conductors (ACSR is common), supports, insulators (pin type up to about 33 kV, suspension above that), sag, corona and skin effect.
• Underground cables: Safer and neater, but costlier and harder to repair.
• Substation: A circuit breaker works under load. An isolator works only off-load.
• Distribution: Feeder (no tappings), distributor (with tappings) and service mains. A radial system is cheaper but less reliable. A ring main is more reliable. A three-phase four-wire system gives 415 V and 230 V.

Quick Formula Sheet for KSEB Electricity Worker Exam 2026