Polytechnic 2nd Year ECE Model Question Paper

Electronics and Communication Engineering – Second Year

Time Allowed: 3 Hours

Instructions

• Two parts: Part A (MCQs, 1 mark each) and Part B (short answer, 5 marks each).
• Attempt all questions.

Part A – Multiple Choice Questions (20 Marks)

1. Which is not an amplifier type? a) Common-emitter b) Common-base c) Common-source d) Cascaded
2. Capacitor in a filter circuit: a) Block DC b) Pass AC c) Store energy d) Amplify
3. Not a modulation type: a) AM b) FM c) Pulse d) Digital
4. Extracting audio from modulated carrier: a) Demodulation b) Modulation c) Amplification d) Filtering
5. Most common semiconductor: a) Silicon b) Germanium c) GaAs d) InP
6. Visible light frequency range: a) 300 GHz–300 THz b) 30 Hz–30 kHz c) 300 kHz–300 MHz d) 30 MHz–30 GHz
7. Unit of capacitance: a) Farad b) Ohm c) Henry d) Coulomb
8. Unit of inductance: a) Farad b) Ohm c) Henry d) Coulomb
9. Radio wavelength inversely proportional to: a) Frequency b) Amplitude c) Phase d) Polarization
10. Charged particle deflected by magnetic field: a) Lorentz force b) Ampère's law c) Faraday's law d) Ohm's law
11. Magnetic field direction around current-carrying wire: a) Right-hand rule b) Left-hand rule c) Ampère's law d) Faraday's law
12. Max transformer efficiency when: a) Same turns b) Different turns c) Same material d) Different materials
13. Full-wave rectifier output: a) Pulsating DC b) Pure DC c) AC d) Square wave
14. Transistor commonly used as switch: a) PNP b) NPN c) JFET d) MOSFET
15. Logic gate for OR: a) AND b) NAND c) NOR d) XOR
16. Binary of decimal 10: a) 1010 b) 0110 c) 0001 d) 1111
17. Memory for permanent data: a) RAM b) ROM c) EEPROM d) Flash
18. Analog vs. digital signals: a) Analog continuous, digital discrete b) Analog discrete, digital continuous c) Analog higher bandwidth d) Analog lower bandwidth
19. Microprocessor purpose: a) Store data b) Process data c) Retrieve data d) Delete data
20. Language for programming microprocessors: a) Machine b) Assembly c) High-level d) Natural

Part B – Short Answer Questions (80 Marks)

1. Principle of PN junction diode operation.
2. Differences between BJT and FET with examples.
3. Concept of modulation; two main types.
4. Block diagram of a simple receiver.
5. Resonance in series RLC circuit; derive resonant frequency formula.
6. Transformer working; step-up/step-down.
7. Full-wave rectifier circuit diagram and operation.
8. Saturated vs. unsaturated digital logic with examples.
9. Flip-flop operation; two main types.
10. Memory addressing; addressing modes in microprocessors.