Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 725 · 40 questions

Remember (Find the topic, use the idea): Find the topic: circuit, safety, formula, component, program, sensor or IoT. Use that lesson’s rule — complete loop, V = I × R, P = V × I, last command wins, true → if part. Safety answers are always: low voltage, dry hands, an adult, never the mains.

1. 1.Which of these is the output? (a) compare with a limit (b) a light level reading (c) an alert on the phone (d) a motion sensor signal
2. 2.🔁 What does “count = count + 1” do? (a) adds 1 to count (b) takes 1 away (c) sets count to 1 (d) prints 1
3. 3.🔍 Which is the odd one out? (a) climb an electric pole (b) build with an adult near (c) use small battery cells (d) take cells out after use
4. 4.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) a wire has come loose
5. 5.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 50 % (c) 5 % (d) 25 %
6. 6.True or false: a spinning top usually has a microcontroller inside. (a) True (b) False
7. 7.True or false: power is measured in watts (W). (a) True (b) False
8. 8.Which job needs a soil moisture sensor? (a) spot someone walking in (b) measure classroom noise (c) water a dry plant (d) open blinds at sunrise
9. 9.Which drawing is the symbol for a junction? (a) triangle against a bar (b) two equal parallel lines (c) many long-short pairs (d) a dot where wires meet
10. 10.🔌 Is a copper wire a conductor or an insulator? (a) an insulator (b) a conductor
11. 11.🔍 Which sensor would you use to open blinds at sunrise? (a) a temperature sensor (b) a distance sensor (c) a light sensor (d) a rain sensor
12. 12.Which drawing is the symbol for a cell? (a) a small empty box (b) a line lifted at a gap (c) many long-short pairs (d) one tall, one short bar
13. 13.🔐 Who should decide which smart devices go in a child’s room? (a) an online stranger (b) the app’s adverts (c) nobody at all (d) a parent or guardian
14. 14.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) quick and clear for all (c) symbols are heavier (d) to hide the circuit
15. 15.🔁 What does a variable do in a program? (a) stores a value (b) measures light (c) joins two wires (d) blinks an LED
16. 16.🔁 total = 0
    for i = 1 to 4 { total = total + i }
    What is total at the end?
17. 17.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) the else part (c) both parts (d) neither part
18. 18.True or false: “a break stops every bulb” is true of a series circuit. (a) True (b) False
19. 19.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
20. 20.⚡ A device works on 6 V and takes 0.5 A. What is its power (in watts)? =
21. 21.🧮 Resistors of 50 Ω, 50 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?
22. 22.🔗 Series or parallel circuit: “each gets the full volts”? (a) series (b) parallel
23. 23.⚙️ What is an actuator? (a) a battery (b) a program (c) an output that acts (d) a sensor
24. 24.💡 Why is house wiring done in parallel? (a) to save copper only (b) so all go off together (c) to make bulbs dim (d) each gets full voltage
25. 25.True or false: “each gets the full volts” is true of a series circuit. (a) False (b) True
26. 26.💡 2 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
27. 27.⚠️ Is it safe to use small battery cells? (a) safe (b) not safe
28. 28.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 LOW
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
29. 29.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
30. 30.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
31. 31.⚠️ Is it safe to stop if a part gets hot? (a) not safe (b) safe
32. 32.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are ON (b) only when both are OFF (c) when either is ON (d) never
33. 33.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 60 (c) 100 (d) 1000
34. 34.Which of these is an input? (a) a light sensor (b) a servo motor (c) a water pump (d) a motor
35. 35.🔋 3 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
36. 36.Which of these mainly makes sound? (a) an exhaust fan (b) a water heater (c) a room heater (d) a buzzer
37. 37.📏 In the water-pipe picture of a circuit, current is like … (a) a narrow pipe (b) the flow of water (c) the pipe colour (d) the water pressure
38. 38.True or false: an LDR senses how bright it is. (a) True (b) False
39. 39.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a metal paper clip across the gap. Does the bulb glow? (a) No (b) Yes
40. 40.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed

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