Renewable Energy & Emerging Trends in Electronics (4361106) - Summer 2025 Solution

Question 1(a) [3 marks]

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Define Renewable Energy and explain its importance.

Answer:

Renewable Energy is energy derived from natural sources that are continuously replenished, such as solar, wind, hydroelectric, biomass, and geothermal energy.

Table: Types of Renewable Energy Sources

Importance:

• Environmental protection: Reduces pollution and greenhouse gases
• Energy security: Reduces dependence on fossil fuels
• Economic benefits: Creates jobs and reduces energy costs

Mnemonic: “SEEB” - Solar, Environmental, Economic, Biomass

Question 1(b) [4 marks]

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Explain Solar Photovoltaic effect & Principle of photovoltaic conversion.

Answer:

Photovoltaic Effect is the generation of electric current when light strikes a semiconductor material.

Working Principle:

• Photon absorption: Light photons hit solar cell surface
• Electron excitation: Electrons gain energy and move to conduction band
• Charge separation: Built-in electric field separates positive and negative charges
• Current generation: Flow of electrons creates DC electricity

Diagram:

Mnemonic: “PACE” - Photons, Absorption, Charge, Electricity

Question 1(c) [7 marks]

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Describe the types of Electric Vehicle (EV) and different Energy sources for EV.

Answer:

Table: Types of Electric Vehicles

Energy Sources for EVs:

• Battery: Lithium-ion batteries store electrical energy
• Fuel Cell: Converts hydrogen to electricity
• Ultracapacitor: Quick energy storage and release
• Flywheel: Mechanical energy storage
• Regenerative Braking: Recovers energy during braking
• Hybrid Sources: Combination of multiple energy sources

Diagram: EV Architecture

Mnemonic: “BHPF-BUFR” - Battery, Hybrid, Plugin, FuelCell - Battery, Ultracap, Flywheel, Regen

Question 1(c) OR [7 marks]

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Discuss different types of Renewable Energy Sources.

Answer:

Table: Renewable Energy Sources Comparison

Emerging Trends:

• Tidal Wave: Ocean wave energy conversion
• Solar Thermal: Concentrated solar power systems
• Hydrogen: Clean fuel from renewable sources

Benefits:

• Sustainability: Never depletes
• Environmental: Minimal pollution
• Economic: Reduces energy costs long-term

Mnemonic: “SWHBG-THS” - Solar, Wind, Hydro, Biomass, Geothermal - Tidal, Hydrogen, Solar thermal

Question 2(a) [3 marks]

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Define Nanotechnology & List Applications of Nanotechnology.

Answer:

Nanotechnology is the science of manipulating matter at atomic and molecular scale (1-100 nanometers).

Applications:

• Electronics: Smaller, faster processors
• Medicine: Drug delivery systems
• Energy: Solar cells, batteries
• Materials: Stronger, lighter composites

Mnemonic: “NEMS” - Nano Electronics, Medicine, Solar

Question 2(b) [4 marks]

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Give Full forms of: UAV, IOT, AI, M2M

Answer:

Table: Technology Abbreviations

Mnemonic: “UIAM” - UAV, IOT, AI, M2M

Question 2(c) [7 marks]

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Describe the block diagram of a drone and its major components.

Answer:

Block Diagram:

graph TD
    A[Flight Controller] --> B[Motors & Propellers]
    A --> C[GPS Module]
    A --> D[IMU Sensors]
    A --> E[Camera]
    F[Battery] --> A
    G[Remote Controller] --> H[Receiver]
    H --> A
    A --> I[Gimbal]

Major Components:

• Flight Controller: Brain of drone, processes sensor data
• Motors & Propellers: Provide thrust and control movement
• Battery: Powers all electronic components
• GPS Module: Provides location and navigation data
• IMU Sensors: Measure acceleration, rotation, magnetic field
• Camera: Captures images and videos
• Gimbal: Stabilizes camera for smooth footage

Working Principle:

• Control: Remote sends commands to receiver
• Processing: Flight controller interprets commands
• Stabilization: IMU sensors maintain balance
• Navigation: GPS provides position feedback

Mnemonic: “FMBGIC” - Flight controller, Motors, Battery, GPS, IMU, Camera

Question 2(a) OR [3 marks]

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Discuss IOT and its importance.

Answer:

Internet of Things (IOT) connects everyday devices to the internet for data exchange and remote control.

Importance:

• Automation: Smart homes and cities
• Efficiency: Optimized resource usage
• Monitoring: Real-time data collection

Mnemonic: “AEM” - Automation, Efficiency, Monitoring

Question 2(b) OR [4 marks]

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Define wearable technology. Name at least three applications of wearable technology.

Answer:

Wearable Technology refers to electronic devices worn on the body to monitor health, fitness, or provide information.

Applications:

• Smart Watches: Fitness tracking, notifications
• Smart Glasses: Augmented reality, navigation
• Health Monitors: Heart rate, blood pressure monitoring

Mnemonic: “WSH” - Watches, Smart glasses, Health monitors

Question 2(c) OR [7 marks]

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Explain with the help of Block diagram Smart Street light control and monitoring.

Answer:

Block Diagram:

graph TD
    A[Light Sensor] --> B[Microcontroller]
    C[Motion Sensor] --> B
    D[Communication Module] --> B
    B --> E[LED Street Light]
    B --> F[Dimming Control]
    G[Central Control System] --> D
    H[Power Supply] --> B

Components:

• Light Sensor: Detects ambient light levels
• Motion Sensor: Detects pedestrian/vehicle movement
• Microcontroller: Processes sensor data and controls lighting
• Communication Module: Wireless connection to control center
• LED Street Light: Energy-efficient lighting
• Dimming Control: Adjusts brightness based on need

Working:

• Auto ON/OFF: Lights turn on at dusk, off at dawn
• Motion Detection: Increases brightness when movement detected
• Remote Monitoring: Central system monitors all lights
• Energy Saving: Dims lights when no activity detected

Mnemonic: “LMCL” - Light sensor, Motion sensor, Controller, LED

Question 3(a) [3 marks]

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Compare Organic and Inorganic electronics.

Answer:

Table: Organic vs Inorganic Electronics

Mnemonic: “MCFP” - Material, Cost, Flexibility, Processing

Question 3(b) [4 marks]

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Write a short note on OPVD.

Answer:

OPVD (Organic Photovoltaic Devices) are solar cells made from organic semiconducting materials.

Characteristics:

• Flexible: Can be made on flexible substrates
• Low-cost: Cheaper manufacturing process
• Lightweight: Suitable for portable applications
• Semi-transparent: Can be integrated into windows

Applications:

• Building Integration: Solar windows
• Portable Devices: Flexible solar chargers
• Wearable Electronics: Solar-powered gadgets

Mnemonic: “FLLW” - Flexible, Low-cost, Lightweight, Windows

Question 3(c) [7 marks]

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Explain Biometric systems and their basic block diagram.

Answer:

Biometric System identifies individuals based on unique biological characteristics.

Block Diagram:

graph TD
    A[Biometric Sensor] --> B[Signal Processing]
    B --> C[Feature Extraction]
    C --> D[Template Matching]
    D --> E[Decision Module]
    F[Database] --> D
    E --> G[Accept/Reject]

Components:

• Sensor Module: Captures biometric data (fingerprint, iris, face)
• Signal Processing: Enhances and cleans captured signal
• Feature Extraction: Identifies unique characteristics
• Database Module: Stores biometric templates
• Matching Module: Compares captured data with stored templates
• Decision Module: Makes final accept/reject decision

Types of Biometrics:

• Fingerprint: Ridge patterns on fingers
• Iris: Eye iris patterns
• Face Recognition: Facial features
• Voice: Voice patterns and characteristics

Applications:

• Security: Access control systems
• Banking: ATM authentication
• Mobile: Phone unlocking
• Border Control: Immigration systems

Mnemonic: “SFEMD” - Sensor, Feature extraction, Matching, Database, Decision

Question 3(a) OR [3 marks]

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List the advantages and applications of organic electronics.

Answer:

Advantages:

• Flexible: Bendable electronic devices
• Low-cost: Cheaper manufacturing
• Large-area: Can cover large surfaces

Applications:

• OLED Displays: Flexible screens
• Solar Cells: Lightweight panels
• RFID Tags: Flexible identification

Mnemonic: “FLL-OSR” - Flexible, Low-cost, Large-area - OLED, Solar, RFID

Question 3(b) OR [4 marks]

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Write a short note on OLED.

Answer:

OLED (Organic Light Emitting Diode) is a display technology using organic compounds that emit light when electric current is applied.

Advantages:

• Self-illuminating: No backlight needed
• High contrast: True black colors
• Flexible: Can be bent and curved
• Energy efficient: Lower power consumption

Applications:

• Smartphones: OLED screens
• TVs: Ultra-thin displays
• Wearables: Smartwatch displays

Mnemonic: “SHFE” - Self-illuminating, High contrast, Flexible, Efficient

Question 3(c) OR [7 marks]

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Explain AR/VR core technology and discuss its applications.

Answer:

AR (Augmented Reality) overlays digital information on real world, while VR (Virtual Reality) creates completely immersive digital environment.

Core Technologies:

• Display Systems: Head-mounted displays, screens
• Tracking Systems: Motion sensors, cameras
• Processing Units: GPU, specialized chips
• Input Methods: Controllers, gesture recognition

AR Applications:

• Gaming: Pokemon Go, mobile AR games
• Education: Interactive learning experiences
• Navigation: GPS overlays on real roads
• Shopping: Virtual try-on experiences

VR Applications:

• Entertainment: Immersive gaming, movies
• Training: Flight simulators, medical training
• Architecture: Virtual building walkthroughs
• Therapy: Treatment of phobias, PTSD

Table: AR vs VR Comparison

Mnemonic: “DTPI-GENT” - Display, Tracking, Processing, Input - Gaming, Education, Navigation, Training

Question 4(a) [3 marks]

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Draw Block Diagram of a Home Solar rooftop system.

Answer:

Block Diagram:

Components:

• Solar Panels: Convert sunlight to DC electricity
• Inverter: Converts DC to AC power
• Battery Storage: Stores excess energy

Mnemonic: “SIB” - Solar panels, Inverter, Battery

Question 4(b) [4 marks]

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Explain working principle of OFET.

Answer:

OFET (Organic Field Effect Transistor) uses organic semiconductors to control current flow.

Working Principle:

• Gate Voltage: Applied voltage creates electric field
• Channel Formation: Electric field modulates conductivity
• Current Control: Source-drain current controlled by gate
• Switching: ON/OFF states for digital applications

Structure:

• Source/Drain: Current injection points
• Gate: Control electrode
• Organic Layer: Active semiconductor material

Mnemonic: “GCCS” - Gate voltage, Channel, Current, Switching

Question 4(c) [7 marks]

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List various Machine learning tools. Discuss any two in brief.

Answer:

Machine Learning Tools:

• TensorFlow: Google’s ML framework
• PyTorch: Facebook’s deep learning library
• Scikit-learn: Python ML library
• Keras: High-level neural network API
• Machine Learning for Kids: Educational platform
• Scratch: Visual programming for ML

TensorFlow:

• Purpose: Deep learning and neural networks
• Features: Large-scale ML, production deployment
• Applications: Image recognition, NLP, recommendation systems
• Advantages: Scalable, extensive documentation

Scikit-learn:

• Purpose: General machine learning algorithms
• Features: Classification, regression, clustering
• Applications: Data analysis, predictive modeling
• Advantages: Easy to use, well-documented

Table: ML Tools Comparison

Mnemonic: “TPSKMS-TF.SL” - TensorFlow, PyTorch, Scikit, Keras, ML4Kids, Scratch - TensorFlow, Scikit-learn

Question 4(a) OR [3 marks]

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Briefly explain Emerging Trends in Renewable Energy.

Answer:

Emerging Trends:

• Floating Solar: Solar panels on water bodies
• Perovskite Cells: Next-generation solar technology
• Green Hydrogen: Clean fuel from renewable sources

Benefits:

• Higher efficiency: Better energy conversion
• Cost reduction: Cheaper renewable energy

Mnemonic: “FPG” - Floating solar, Perovskite, Green hydrogen

Question 4(b) OR [4 marks]

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Give Full forms of: AR, OLED, OPVD, OFET

Answer:

Table: Technology Full Forms

Mnemonic: “AOOO” - AR, OLED, OPVD, OFET

Question 4(c) OR [7 marks]

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Explain Block diagram of Raspberry Pi.

Answer:

Block Diagram:

graph TD
    A[ARM Processor] --> B[RAM Memory]
    A --> C[GPIO Pins]
    A --> D[USB Ports]
    A --> E[HDMI Output]
    A --> F[Ethernet Port]
    G[MicroSD Card] --> A
    H[Power Supply] --> A
    A --> I[Audio/Video]

Components:

• ARM Processor: Central processing unit (Quad-core)
• RAM Memory: System memory (1GB-8GB)
• GPIO Pins: 40 pins for interfacing sensors/devices
• USB Ports: Connect peripherals
• HDMI Output: Video display connection
• Ethernet Port: Network connectivity
• MicroSD Card: Storage for OS and data
• Power Supply: 5V micro-USB or USB-C

Features:

• Operating System: Raspberry Pi OS (Linux-based)
• Programming: Python, C++, Scratch support
• Connectivity: Wi-Fi, Bluetooth built-in
• Expandability: Camera, display connectors

Applications:

• IoT Projects: Home automation
• Education: Learning programming
• Robotics: Robot control systems
• Media Center: Home entertainment

Mnemonic: “ARGC-EPMS” - ARM, RAM, GPIO, Connectivity - Ethernet, Power, MicroSD, Storage

Question 5(a) [3 marks]

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Interface LED with Raspberry Pi.

Answer:

Circuit Connection:

Python Code:

import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)
GPIO.setup(18, GPIO.OUT)

while True:
    GPIO.output(18, GPIO.HIGH)  # LED ON
    time.sleep(1)
    GPIO.output(18, GPIO.LOW)   # LED OFF
    time.sleep(1)

Mnemonic: “GPIO-RC” - GPIO pin, Resistor, Code

Question 5(b) [4 marks]

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Explain Pandas python library For Machine Learning.

Answer:

Pandas is a Python library for data manipulation and analysis, essential for ML data preprocessing.

Key Features:

• DataFrame: Tabular data structure
• Data Cleaning: Handle missing values, duplicates
• Data Import: Read CSV, Excel, JSON files
• Data Analysis: Statistical operations, grouping

ML Applications:

• Data Preprocessing: Clean and prepare datasets
• Feature Engineering: Create new features from data
• Data Exploration: Understand data patterns
• Data Transformation: Normalize, scale data

Common Functions:

import pandas as pd
df = pd.read_csv('data.csv')    # Load data
df.info()                       # Data info
df.describe()                   # Statistics

Mnemonic: “DCIF” - DataFrame, Cleaning, Import, Functions

Question 5(c) [7 marks]

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Explain types of machine learning techniques: supervised, unsupervised and reinforcement learning.

Answer:

Table: Machine Learning Types

Supervised Learning:

• Definition: Learns from input-output pairs
• Process: Training with known answers
• Applications: Email spam detection, image recognition
• Algorithms: Linear regression, decision trees, neural networks

Unsupervised Learning:

• Definition: Finds hidden patterns in data
• Process: No target variable provided
• Applications: Customer segmentation, anomaly detection
• Algorithms: K-means clustering, PCA, hierarchical clustering

Reinforcement Learning:

• Definition: Learns through trial and error
• Process: Agent interacts with environment
• Applications: Game AI, autonomous vehicles, robotics
• Components: Agent, environment, rewards, actions

Diagram: ML Learning Process

graph TD
    A[Data] --> B{Learning Type}
    B --> C[Supervised]
    B --> D[Unsupervised]
    B --> E[Reinforcement]
    C --> F[Prediction Model]
    D --> G[Pattern Discovery]
    E --> H[Decision Policy]

Mnemonic: “SUR-PLR-CPD” - Supervised, Unsupervised, Reinforcement - Prediction, Learning, Rewards - Classification, Patterns, Decisions

Question 5(a) OR [3 marks]

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Explain NumPy python library For Machine Learning.

Answer:

NumPy is fundamental library for numerical computing in Python, essential for ML operations.

Key Features:

• Arrays: Multi-dimensional array objects
• Mathematical Functions: Linear algebra operations
• Broadcasting: Operations on different sized arrays

ML Applications:

• Data Storage: Efficient numerical data storage
• Matrix Operations: Neural network computations
• Mathematical Computations: Statistical operations

Mnemonic: “AMB” - Arrays, Mathematical functions, Broadcasting

Question 5(b) OR [4 marks]

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Write Installation steps of Raspberry Pi OS on SD card using Raspberry Pi Imager.

Answer:

Installation Steps:

1. Download: Install Raspberry Pi Imager from official website
2. Insert SD Card: Connect SD card (16GB+) to computer
3. Select OS: Choose Raspberry Pi OS from list
4. Select Storage: Choose SD card as target
5. Write: Click “Write” to flash OS to SD card
6. Eject: Safely remove SD card after completion

Pre-configuration Options:

• Enable SSH: For remote access
• Set Username/Password: Security credentials
• Configure Wi-Fi: Network settings

Mnemonic: “DISWS-ESP” - Download, Insert, Select OS, Write, Storage - Enable SSH, Set credentials, Pre-configure

Question 5(c) OR [7 marks]

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Interface Temperature and humidity sensors with Raspberry Pi and write Python Program for it.

Answer:

Circuit Connection:

Python Program:

import Adafruit_DHT
import time

# Sensor type and GPIO pin
sensor = Adafruit_DHT.DHT22
pin = 4

while True:
    try:
        # Read sensor data
        humidity, temperature = Adafruit_DHT.read_retry(sensor, pin)
        
        if humidity is not None and temperature is not None:
            print(f'Temperature: {temperature:.1f}°C')
            print(f'Humidity: {humidity:.1f}%')
        else:
            print('Failed to read sensor data')
            
        time.sleep(2)  # Wait 2 seconds
        
    except KeyboardInterrupt:
        print("\nProgram stopped")
        break

Required Library:

pip install Adafruit_DHT

Components Used:

• DHT22: Temperature and humidity sensor
• Raspberry Pi: Processing unit
• Python: Programming language
• Adafruit Library: Sensor interface library

Features:

• Real-time Reading: Continuous monitoring
• Error Handling: Handles sensor read failures
• Data Display: Shows temperature and humidity values
• User Control: Keyboard interrupt to stop program

Applications:

• Weather Station: Local weather monitoring
• Home Automation: Climate control systems
• Agriculture: Greenhouse monitoring
• Industrial: Environmental monitoring

Mnemonic: “DHT-RPL” - DHT sensor, Raspberry Pi, Python, Library