About this previous year paper
This question paper evaluates a student's understanding of semiconductor devices, diode circuits, transistor configurations, FETs, MOSFETs, operational amplifiers, CRO, power supplies, and rectifiers.
It is divided into three sections covering conceptual definitions, analytical explanations, and detailed device-level derivations.
SECTION – A (10 × 2 = 20 Marks)
This section contains ten short-answer questions requiring definitions, comparisons, small calculations, or circuit sketches.
Topics include:
Properties of Si vs Ge semiconductors
Depletion layer in a diode
Bulk resistance of a diode
Double-ended diode clipper circuit
Output waveform across RL (given op-amp protective circuit)
Source transformation (voltage source → current source)
Ohmic region in FET
Percentage change in β for change in α
Need for triggering in CRO
Specifications of unregulated power supply
This section tests basic semiconductor theory, small derivations, and device fundamentals.
SECTION – B (5 × 10 = 50 Marks)
Students must attempt any five descriptive questions involving diagrams, device characteristics, amplifier analysis, and op-amp applications.
Topics include:
Input & output characteristics of Zener and Varactor diodes
Common Base transistor configuration and Voltage Divider Bias
Loading effect due to amplifier input impedance
JFET transconductance curve
Self-bias JFET amplifier circuit
CMOS inverter working
Op-amp applications: integrator, summing amplifier, zero-crossing detector
Voltage gain, input impedance & bandwidth of inverting amplifier with negative feedback
Characteristics of Digital Voltmeter
CRO controls and measurement of power supply performance
This section evaluates device behavior, circuit analysis, biasing, op-amp design, and instrumentation understanding.
SECTION – C (2 × 15 = 30 Marks)
Students must attempt any two long-answer questions.
Topics include:
Half-Wave Rectifier
Derivation of ripple factor
Analysis of the given diode clipping circuit (Fig. 2) with output waveform
Transistor & MOSFET
CE configuration: circuit, input/output characteristics
Working of enhancement and depletion-mode MOSFET
Derivation of JFET transconductance (gₘ) equation
Operational Amplifier & CRO
Op-amp block diagram, equivalent circuit & ideal characteristics
CRO functional blocks: deflection amplifier & CRT
These questions test deep theoretical understanding, mathematical derivations, and detailed electronic circuit analysis.