Question 1: Explain the purpose of a switch in an electronic circuit. How does it control the flow of electricity?

Answer: A switch opens or closes the circuit, allowing or stopping the flow of electricity. When closed, it completes the circuit, enabling devices to turn on; when open, it breaks the circuit, turning devices off.

Question 2: Describe the main components of a simple electronic circuit that could be used to turn on a light bulb.

Answer: The main components include a power source (battery), a switch, wires to connect the components, and a light bulb. The circuit completes when the switch is closed, allowing current to flow and the bulb to light.

Question 3: Design Brief: You need to create a small electronic device that turns on a fan when a room gets too warm. List the main components you would use and explain their role.

Answer: Main components include a temperature sensor to detect heat, a microcontroller to process signals, a relay to switch the fan on and off, a power supply, and the fan itself. The sensor detects temperature; the microcontroller activates the relay to turn on the fan when needed.

Question 4: Sketch a basic circuit diagram for a system that automatically turns on a light when it gets dark. Include the key components and connections.

Answer: A correct sketch would show a light sensor (such as a photoresistor) connected in series with a relay or transistor, controlling the power to a light bulb. The sensor detects darkness and triggers the switching component to turn the light on.

Question 5: Identify and explain the function of a transistor in an electronic circuit.

Answer: A transistor acts as a switch or amplifier. It can control a large current with a smaller input current, allowing it to turn devices on or off or amplify signals within the circuit.

Question 6: Create a labelled diagram of a simple series circuit that includes a battery, two light bulbs, and a switch. Label each component clearly.

Answer: A correct diagram would show a battery connected in series with two light bulbs and a switch. The labels should clearly identify each component and show the proper connections in a series layout.

Question 7: Explain the difference between a series circuit and a parallel circuit. Provide one advantage of each.

Answer: In a series circuit, components are connected end-to-end in a single loop, so current flows through each component in sequence. In a parallel circuit, components are connected across the same voltage source, so each component has its own path. An advantage of series is simplicity; an advantage of parallel is that if one component fails, others can still work.

Question 8: Design Brief: You are tasked with designing a burglar alarm system for a door. Describe how you would use sensors and electronic components to create this system.

Answer: The system could include a magnetic reed switch on the door, connected to a circuit with a buzzer or siren. When the door opens, the switch breaks the circuit, activating the alarm. A power supply and possibly a microcontroller could be used to control the system and add features like delay or remote alerts.

Question 9: Draw a simple block diagram showing the main parts of an electronic security system that detects movement and triggers an alarm.

Answer: A correct block diagram would include a motion sensor (like an PIR sensor), a processing unit (microcontroller), an alarm device (buzzer or siren), and a power supply. Arrows should show the flow from detection to alarm activation.

Question 10: What is the role of a resistor in an electronic circuit? How does changing its value affect the circuit?

Answer: A resistor limits the flow of current in a circuit. Increasing its value reduces current flow, while decreasing its value allows more current to pass. It helps protect components and control circuit behavior.