Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 197 · 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 “wait 500 ms” do? (a) pauses for half a second (b) turns the LED off (c) waits 500 seconds (d) blinks 500 times
2. 2.⚡ A fan changes electrical energy mainly into which kind of energy? (a) light energy (b) chemical energy (c) movement energy (d) sound energy
3. 3.🔁 What does “count = count + 1” do? (a) prints 1 (b) sets count to 1 (c) adds 1 to count (d) takes 1 away
4. 4.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 1000 (c) 100 (d) 60
5. 5.💡 What does LED stand for? (a) large electric dial (b) light-emitting diode (c) low energy device (d) light energy dial
6. 6.🔦 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) Yes (b) No
7. 7.🔌 Which part of a screwdriver should an electrician hold? (a) the steel shaft (b) the metal tip (c) the plastic handle (d) the bare end
8. 8.What does a fuse do? (a) lets current go one way (b) makes things spin (c) has coloured bands (d) blows if current is high
9. 9.🔐 Is it a good or a risky habit to log out of shared phones? (a) risky habit (b) good habit
10. 10.Which of these is not safe? (a) touch a fallen wire (b) take cells out after use (c) keep drinks far away (d) stay away from pylons
11. 11.Which of these is true of a parallel circuit? (a) bulbs share the voltage (b) used in house wiring (c) a break stops every bulb (d) a single current path
12. 12.True or false: a slide switch springs back when let go. (a) True (b) False
13. 13.⚡ What does an exhaust fan mainly change electricity into? (a) light (b) sound (c) heat (d) movement
14. 14.🔺 A 2 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
15. 15.⚡ What does an electric drill mainly change electricity into? (a) movement (b) heat (c) sound (d) light
16. 16.Which of these is safe? (a) take cells out after use (b) climb an electric pole (c) open a phone charger (d) fly a kite near wires
17. 17.🔍 Which is the odd one out? (a) touch a fallen wire (b) use mains for a project (c) use small battery cells (d) poke things in a socket
18. 18.⚠️ Is it safe to touch a fallen wire? (a) safe (b) not safe
19. 19.True or false: to reuse one password is a risky habit. (a) True (b) False
20. 20.True or false: “an alert on the phone” is the input. (a) False (b) True
21. 21.🔢 To run one loop of a plant-watering program, what comes right after “compare with the limit”? (a) read the soil sensor (b) switch the pump on/off (c) wait a few seconds
22. 22.True or false: on an LED, the shorter leg is the anode (+). (a) True (b) False
23. 23.🔘 Which kind of switch stays where you flip it? (a) a reed switch (b) a push button (c) a toggle switch (d) a slide switch
24. 24.🌈 In the resistor colour code, which number does grey stand for?
25. 25.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is ON, B is OFF, C is ON and D is OFF. Does the bulb glow? (a) No (b) Yes
26. 26.⚡ A device works on 1.5 V and takes 1 A. What is its power (in watts)? =
27. 27.⚠️ Who should be with you when you build a circuit? (a) a trusted adult (b) a younger child (c) nobody (d) a stranger online
28. 28.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is ON, B is ON and C is OFF. Does the bulb glow? (a) No (b) Yes
29. 29.🔺 A current of 1.5 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
30. 30.True or false: “used in house wiring” is true of a parallel circuit. (a) False (b) True
31. 31.True or false: to take cells out after use is not safe. (a) True (b) False
32. 32.🔁 repeat 2 times { repeat 6 times { beep } }
    How many beeps are there?
33. 33.Which of these is a risky habit? (a) read app permissions (b) set a strong password (c) share the Wi-Fi key (d) set up with a parent
34. 34.⚡ A cell changes stored chemical energy into which kind of energy? (a) sound energy (b) wind energy (c) electrical energy (d) nuclear energy
35. 35.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) True (b) False
36. 36.🧮 Two equal 200 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
37. 37.💡 6 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. Bulbs 4 and 5 are taken out of their holders. How many bulbs glow?
38. 38.Which of these is a conductor? (a) a rubber eraser (b) a dry cork (c) a plastic straw (d) a graphite rod
39. 39.Which of these is an output? (a) a temperature sensor (b) a sound sensor (c) a turning knob (d) a motor
40. 40.Which of these gives us electricity? (a) a television (b) a battery (c) a water pump (d) a computer

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