Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 350 · 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.🔘 What does a switch do in a circuit? (a) changes the voltage (b) opens or closes the loop (c) makes electricity (d) stores current
2. 2.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 680 Ω resistor? (a) grey-blue-brown (b) blue-grey-black (c) blue-grey-red (d) blue-grey-brown
3. 3.📏 How many watts (W) is 1.1 kW?
4. 4.🤖 “if (A AND B)” is true when … (a) only A is true (b) both A and B are true (c) both are false (d) only B is true
5. 5.True or false: “one bulb out, all go out” is true of a series circuit. (a) False (b) True
6. 6.Which drawing is the symbol for a switch? (a) a plain rectangle (b) a line lifted at a gap (c) many long-short pairs (d) triangle against a bar
7. 7.🔍 Which is the odd one out? (a) a water heater (b) a rice cooker (c) a room heater (d) an LED lamp
8. 8.Which of these is not an IoT device? (a) a Wi-Fi weather station (b) a Wi-Fi doorbell camera (c) an app-controlled bulb (d) a paper calendar
9. 9.🔍 Which sensor would you use to switch on lamps at dusk? (a) a gas sensor (b) a light sensor (c) a sound sensor (d) a soil moisture sensor
10. 10.🧩 Which component stores a little charge? (a) transistor (b) fuse (c) LED (d) capacitor
11. 11.🔍 Which is the odd one out? (a) a steel coin (b) a paper strip (c) a graphite rod (d) a brass key
12. 12.True or false: to use LED lamps wastes electricity. (a) True (b) False
13. 13.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 50 % (c) 5 % (d) 0 %
14. 14.🔺 A current of 0.1 A flows when 0.8 V is joined across a resistor. What is its resistance (in ohms)?
15. 15.True or false: to throw cells in a fire is safe. (a) True (b) False
16. 16.Which of these is not an IoT device? (a) a plain wall switch (b) a smart energy meter (c) an app-controlled bulb (d) a fitness band with app
17. 17.🔋 5 identical 1.5 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
18. 18.⚡ A device works on 5 V and takes 1 A. What is its power (in watts)? =
19. 19.⚡ A 4.5 W device works on 9 V. What current does it take (in amperes)? =
20. 20.True or false: triangle against a bar is the symbol for a resistor. (a) True (b) False
21. 21.🔍 Which is the odd one out? (a) touch a switch when wet (b) climb an electric pole (c) keep drinks far away (d) use mains for a project
22. 22.⏱️ What does “wait 500 ms” do? (a) blinks 500 times (b) turns the LED off (c) pauses for half a second (d) waits 500 seconds
23. 23.🌐 Is an app-controlled bulb an IoT device? (a) an IoT device (b) not an IoT device
24. 24.🧮 Two resistors in parallel give a total that is … (a) less than either one (b) their sum (c) always zero (d) more than either one
25. 25.What does a push button do? (a) closes when tipped over (b) closes near a magnet (c) flips up or down (d) works only while pressed
26. 26.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a steel spoon. Does the bulb glow? (a) No (b) Yes
27. 27.🌐 In an IoT system, which part carries the data? (a) Wi-Fi (b) cloud server (c) sensor (d) microcontroller
28. 28.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) becomes zero (c) gets bigger (d) gets smaller
29. 29.True or false: resistance is measured in amperes (A). (a) False (b) True
30. 30.🔢 To get a sensor reading onto a phone, what comes right after “the board reads it”? (a) the app shows it (b) it is sent by Wi-Fi (c) the sensor measures (d) the cloud stores it
31. 31.✏️ Why do engineers draw circuits with symbols? (a) quick and clear for all (b) symbols are heavier (c) to hide the circuit (d) to make it colourful
32. 32.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 53 %. What happens? (a) pump ON (b) pump OFF
33. 33.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) by Wi-Fi (c) not joined (d) in parallel
34. 34.True or false: a push button works only while pressed. (a) False (b) True
35. 35.🔺 A 3 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
36. 36.🔋 Does a solar panel give electricity or use electricity? (a) uses electricity (b) gives electricity
37. 37.Which job is done by the reset button? (a) brings power and code (b) shows the board is on (c) connect sensors and LEDs (d) restarts the program
38. 38.🔁 count = 0
    repeat 7 times { count = count + 9 }
    What is count at the end?
39. 39.🔺 A current of 3 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
40. 40.⚡ What does a doorbell mainly change electricity into? (a) heat (b) movement (c) sound (d) light

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