Kerala Plus Two Electronics (DHSE) case studies
Kerala Plus Two Electronics (DHSE) · Put your knowledge to work in context.
The Kerala Higher Secondary (Plus Two) Electronics course is a two-year programme offered by the Directorate of Higher Secondary Education (DHSE), Kerala, typically taken in Classes 11 and 12. It is designed for students who want a practical, circuit-oriented introduction to electronics alongside their general higher secondary subjects, and it often serves as a stepping stone to diploma or degree programmes in electronics, instrumentation, or engineering. The written examination assesses theory across semiconductor devices, power supplies and rectifiers, amplifiers and oscillators, digital electronics and logic circuits, communication systems and modulation, microcontrollers and embedded basics, and electronic instruments and troubleshooting. A school-level practical assessment covers laboratory skills and project work. The Kerala Plus Two Electronics (DHSE) case studies are 5 cases and about 2,721 words.
1Relay driver that chatters and overheats
A Plus Two project uses a BC547 NPN transistor to switch a 12 V relay from a 5 V logic output. The relay coil measures 400 Ω.
586 words, about 3 min212 V supply that loses regulation at full load
A student builds a 12 V, 0.5 A regulated supply using a 230 V/12 V transformer, a bridge rectifier, a 2200 µF filter capacitor and a 7812 regulator. At no load the output is 12.1 V.
531 words, about 3 min3Three-sensor alarm that sounds with all sensors open
A Plus Two team builds a three-sensor alarm using 7400 NAND gates. The buzzer must sound when at least two of A, B, C are HIGH.
575 words, about 3 min4AM modulator that claims 8 W from an 8 V peak carrier
A student builds a simple AM modulator for a 1 MHz carrier. With no audio, the carrier envelope is 8.0 V peak.
514 words, about 3 min5DMM reads 4.09 V across a 2.2 MΩ divider
A student measures the gate bias of a MOSFET preamplifier. The divider is R1 = 2.2 MΩ from +9.0 V to node X, and R2 = 2.2 MΩ from X to ground.
515 words, about 3 min