ISC Class 12 Syllabus 2028 Electricity and Electronics

ISC
INDIAN SCHOOL CERTIFICATE
EXAMINATION

YEAR 2028

ELECTRICITY
&
ELECTRONICS
(866)

Developed by:
Research, Development and Curriculum Division (RDCD)
CISCE

January 2026
____________________________________________________________________________________________

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Council for the Indian School Certificate Examinations (CISCE)

MISSION STATEMENT

The Council for the Indian School Certificate
Examinations is committed to serving the nation's
children, through high quality educational
endeavours, empowering them to contribute towards
a humane, just and pluralistic society, promoting
introspective living, by creating exciting learning
opportunities, with a commitment to excellence.

ETHOS OF CISCE

Trust and fair play.
Minimum monitoring.
Allowing schools to evolve their own niche.
Catering to the needs of the children.
Giving freedom to experiment with new ideas
and practices.
Diversity and plurality - the basic strength for
evolution of ideas.
Schools to motivate pupils towards the
cultivation of:
Excellence - The Indian and Global
experience.
Values - Spiritual and cultural - to be the bedrock
of the educational experience.
Schools to have an 'Indian Ethos', strong roots in
the national psyche and be sensitive to national
aspirations.

CLASS XII
There will be two papers in the subject:
Paper I: Theory - 3 hours…80 marks
Paper II: Project Work ... 20 marks

PAPER I (THEORY) : 80 MARKS
1. Distribution of electric power. Idea of a simple distribution system. Mention of the local power system should
be made.
Overhead and underground cables: advantages and uses. D.C and A.C distribution systems: D.C 2 wire
system, 3 wire system; AC distribution transformer (3 phase 3 wire system, 3 phase 4 wire system).

2. The D.C. generator and motor. Use of split-ring commutators; constructional features. Shunt series and
compound field connections and their characteristics. Starting of D.C. motors. Ideas on back e.m.f.
Single loop D.C. generator (circuit diagram); parts of a practical generator, lap and wave windings of
armature conductors; armature reactions, commutation and period of commutation (T c ), use of interpoles,
ϕ PN Z
emf equation E g = × (derivation not required); types of generators; Excitation of poles: Self-excited
60 A
and separately excited; generator construction: shunt, series & compound types; no-load and load
characteristics, voltage, current and power equations, critical resistance; causes of failure to build up voltage
for generators, applications and simple numericals.
Motors: Working principle of a DC motor; voltage equation; significance of back emf; D.C motor
characteristics. Types of D.C motor constructions- shunt, series and compound; necessity of motor starter
and protective devices; power equation applications, uses and numericals.

3. The A.C. motor. Ideas on A.C. motors (single phase only). The rotating field. Methods of shunting:
capacitance start, split phase start. Single-phase induction motor types.
A.C. motors (single phase only); idea of rotating magnetic field: split phase start, capacitor start single phase
induction motor types. Uses of AC motors.

4. Wires, cables and electrical wiring. Construction of various types in domestic and industrial use. (Solid and
stranded cables – how insulated and protected. Flexes). Selection of cable sizes, voltage drop and simple
calculation on current-carrying capacity. (Linking of size of cables and flexes with maximum current flow
particularly in relation to the circuits below. Regulation B 23 (voltage drop). Brief description of the wiring
systems. Simple circuitry. (Separation of lighting and power circuits. Layout of lighting circuits. Switch in
phase line. Dual switching of lamps. Layout of power circuits - ring and spur/ tree systems.) types -
limitations). Introduction to rules and regulations, both local and that of I.E.E. (Sequence of equipment).
Effects of overloading. Protection of circuits and individuals by (a) fuses and trips, (b) earthing of metal, (c)
mechanical protection of cables. Regulations for bathrooms. Commonsense appreciation of dangerous
practices (Simple testing).
Different types of insulations used in cables; Vulcanised Indian Rubber (VIR), Tough Rubber Sheathed (TRS),
Poly Vinyl Chloride (PVC).

5. Electrical accessories. Structure and uses of various types of switches, power outlets, lamp holders, ceiling
roses and junction boxes. (Familiarity with these is expected - detailed knowledge of structure is not required).
Where and how they are used.
Structure and uses of switches; types: quick break knife switch, main switch, metal clad switch, air break
switch, tumbler switch, piano-key switch, finger touch switch; essential qualities of a switch and its position
in circuits and layouts; power outlets – Plug and Sockets; lamp holders types: bracket holder, batten holder,
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pendant holder, angle holder. Ceiling roses; junction boxes. Where and how they are used.

6. Introduction to electronics. Concept of electron flow. Common components employed in electronic circuits;
resistors, capacitors and inductors; their structure, types and uses.
Concept of electron flow; passive components employed in electronic circuits. Types of Resistors: wire wound,
carbon composition type, variable type (potentiometers, rheostat); colour code. Types of Inductors: air core,
iron-core, ferrite core inductors. Types of Capacitors: fixed and variable types. Fixed type: electrolytic
capacitor, non-electrolytic (paper capacitors, mica capacitor, ceramic capacitors); variable type - ganged
capacitors, their structure, types, voltage equations and uses.

7. Diodes. Thermionic diode; semiconductor diode. Structure of vacuum diode and semiconductor diode.
Thermionic diode: construction, operation characteristics of vacuum diodes; A.C and D.C plate resistances,
space charge, space charge limiting region.
Semiconductor diodes: bonds in semiconductors, crystal structure of Germanium and Silicon; effect of
temperature on semiconductor; concept of hole current; intrinsic and extrinsic semiconductors; doping, n-
type, p type semiconductors, energy band diagrams; majority and minority charge carries; properties of p-n
junction diode, forward bias and reverse bias diagrams and graphs; volt-ampere characteristics of p-n
junction. Definitions of the following: break down voltage, knee voltage, maximum forward current, Peak
inverse voltage (PIV), maximum power rating.

8. Power supply for electronic apparatus. Mains transformer. The diode; half wave, full wave and bridge
rectifiers, voltage doubler. Filters; RC filters, chokes, bleeder resistance and its functions.
Mains transformer; semiconductor diodes as half wave rectifier, full wave rectifier, bridge rectifier. Forward
resistance, forward current, reverse current, derivation for: d.c (average current I dc ). Root mean square (rms)
current (I rms ), efficiency of rectification (η); advantages, disadvantages and uses, ripple factors; simple
numericals.
Voltage doublers: Types of filters: RC filter, choke Input (I/P) filter, π-section filter. Input (I/P) and Output
(O/P) graphs. Zener diode for voltage stabilisation, importance of series Resistor in the stabilization circuit,
simple numericals. Chokes, bleeder resistors and their functions.

9. Vacuum triode. Structure of the vacuum triode valve. The control grid. Triode valve characteristics. Triode
parameters; anode resistance, mutual conductance and amplification factors; relationship between the above
parameters. Triode as a voltage amplifier. Bias voltage, cathode resistor and cathode bypass capacitor.
Structure of the vacuum triode, control grid, triode value characteristics, grid cut off voltage. Plate
characteristics, mutual characteristics; vacuum tube constants (Triode parameters), relationship between
them, simple numericals. Triode as voltage amplifier: bias voltage, cathode resistor and cathode bypass
capacitor; current in vacuum, causes of tube failure. Significance of vacuum in tubes.

10. Semiconductor Transistors. The junction transistor: PNP and NPN types. Introduction to various methods of
construction; their characteristics including handling procedures and precautions.
Self-explanatory.

11. Transistor amplifier. Introduction to the common-base, common emitter and common collector amplifiers.
Comparison of the voltage, current and power gains and input and output resistances (elementary approach
only). Phase relationship. Bias stabilization.
Modes of connections: Common-Base (CB), Common-Emitter (CE), Common-Collector (CC) amplifiers:
current amplification factors (∝, β and 𝛾𝛾) and their relationship. Simple numericals on the above.
I/P and O/P characteristics, comparison of the voltage, current and power gain, I/P & O/P resistance
(elementary approach only). Phase relationship, bias stabilization, single stage RC coupled amplifier circuit,
bias circuit, emitter bypass capacitor, transistor current equation ∆ I E = ∆I B +∆I C . Phase reversal in CE
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mode.

12. The amplifier. A typical amplifier voltage and power amplification. Matching of the power output stage to a
speaker.
Voltage Amplifier (RC Coupled) circuit; Power amplifier circuit, impedance matching of the power (O/P)
stage to the speaker; advantages, disadvantages, frequency responses (qualitative), Applications. Differences
between transistors and tubes.

13. Apparatus for reproducing and recording sounds. Range of hearing, recording and reproducing.
Characteristics of microphones; types of microphones: carbon, crystal, moving-coil and ribbon types. The
common types of gramophone pick-ups. The earphone, crystal and magnetic tapes. The moving-coil
loudspeakers; permanent magnet. Electrostatic speaker.
Construction, working, advantages and disadvantages of the above.

14. Common types of electronic measuring instruments. Valve voltmeters, transistorized voltmeter, signal
generator, oscilloscope, use and care of the above instruments.
Simple circuit diagrams of the above instruments are expected.
Valve voltmeters (VTVM), transistorized voltmeter, signal generator, oscilloscope (CRT); uses of
Oscilloscope to measure: (a) the peak value of an ‘ac’ voltage; (b) the frequency of an electrical signal; (c)
the time interval (can be used as a clock). Multimeter used as voltmeter, ohm-meter and ammeter.

PAPER II (PROJECT WORK) : 20 MARKS
In addition to the syllabus prescribed above, candidates are also required to be assessed in Project Work. The
Project work will be assessed by the subject teacher and the Visiting Examiner appointed locally and approved by
CISCE.
All candidates will be required to have completed two projects from any topic/s covered in theory.
Mark allocation for each project (10 marks) :

S.No. Criteria Marks
1. Title of the Project and Introduction 1
2. Content 3
3. Presentation and originality 2
4. Conclusion/Comments/Summary 1
5. Viva-Voce (Visiting Examiner) 3
TOTAL 10

List of suggested assignments for Project Work:

1. Electrical accessories (any five), meters and equipment (any three) used in the laboratory (along with
precautions to be observed).
Accessories (tools) used in Laboratory: Soldering gun, soldering stand, solder (lead), nose plier, wire
stripper, line tester, tag-board, breadboard, general purpose printed circuit board (PCB).
Meters and equipment: DC milliammeter, AC milliammeter, DC Voltmeter, AC voltmeter, Digital Multimeter,
Variable DC power supply, Fixed DC power supply, Audio signal generator, Cathode Ray Oscilloscope
(CRO).
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2. Electrical Cables, their types, uses and specifications. (Any 5 types, with one use and important specifications).
3. Measuring the values of different types of:
(i) resistors using colour code
(ii) capacitors using code number .
Writing the procedure to measure the values of resistances, capacitances and inductances using multimeter.
4. Different types of switches (any five), circuit protecting devices and their specifications.
Switches: single-pole, single-throw (SPST), single-pole, double-throw (SPDT), double-pole, single-throw
(DPST), double-pole, double-throw (DPDT), Rotary switch, Push Button switch, relay. Miniature circuit
breaker (MCB), fuse, fuse holder (show samples), switch action (continuity and discontinuity using
multimeter) Specifications; current and voltage ratings.
5. Distribution of electric power (D.C and A.C distribution) using overhead and underground cables along with
their advantages and uses.
6. V-I Characteristics of a semiconductor diode (PN), its types and use of any one type of semiconductor diode.
7. V-I Characteristics of a Zener Diode and its use as a voltage regulator.
8. Half wave and Full wave rectifier (either centre-tapped or bridge type) with/without filter circuit.
9. Electrical accessories (Power outlets, lamp holders, ceiling roses and junction boxes) their structure and uses.
10. Simple circuitry of lighting and power circuits (domestic use), their layout and limitations, following IEE
regulations.
11. Principle, construction and working of DC motor with explanation of any one type of DC motor.
12. Characteristics of DC generator and DC motor.
13. Types of microphones (any two) giving their construction, working and uses with diagrams.
14. Types of loudspeakers (any two) giving their construction, working and uses with diagrams.
15. Construction and working principle of power supply including common faults, causes, testing and repair.
16. Multimeters and their types including functions of any one type of multimeter.
17. Transistor Audio Power Amplifiers (any two types), their advantages, disadvantages and uses.
18. Principle, construction, working and uses of Cathode Ray Oscilloscope.
19. Identify a diode, a transistor, a LED, a resistor, an IC (integrated circuit), and a capacitor from a assorted
collection of given items and an analog multimeter.
20. Prepare a working model on any one of the following and prepare a brief report highlighting the components
used, circuit diagram and a step-by-step procedure:
(i) Automatic Traffic Signal System using suitable combination of logic gates
(ii) Basic gates (OR, AND, NOT) using NAND gates
(iii) FM Radio Receiver
(iv) Fire Alarm System
(v) Electronic Lock
(vi) Stepper Motor Controller
(vii) Water Level Indicator
(viii) Mobile Charger

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NOTE: No question paper for Project work will be set by CISCE.

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SAMPLE TABLE FOR PROJECT WORK

S. Unique PROJECT 1 PROJECT 2 TOTAL
No. Identification MARKS
Number A B C D E F G H I J
(Unique ID) Teacher Visiting Average Viva- Total Teacher Visiting Average Viva-Voce Total (E + J)
of the Examiner Marks Voce by Marks Examine Marks by Marks
candidate (A + B ÷ Visiting (C + D) r (F + G ÷ Visiting (H + I)
2) Examine 2) Examiner
r
7 Marks 7 Marks 7 Marks 3 Marks 10 7 Marks 7 Marks 7 Marks 3 Marks 10 Marks 20
Marks Marks
1

2

3

4

5

6

7

8

9

10

*For breakup of the 7 Marks to be awarded separately by the Teacher and the Visiting Examiner, please refer to the table giving the criteria for mark
allocation for each project.

NOTE: VIVA-VOCE (3 Marks) for each Project is to be conducted only by the Visiting Examiner and should be based on the Project only.

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