Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 36 · 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 is the odd one out? (a) a plastic straw (b) a dry cork (c) a wooden stick (d) a brass key
2. 2.True or false: a plastic ruler is a conductor. (a) False (b) True
3. 3.True or false: triangle against a bar is the symbol for a diode. (a) True (b) False
4. 4.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 3.5 V supply. What current flows (in mA)?
5. 5.🧩 A capacitor in a circuit can … (a) measure heat (b) store charge briefly (c) spin a wheel (d) make light
6. 6.🔘 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 ON. Does the bulb glow? (a) Yes (b) No
7. 7.🤖 Microcontroller or laptop: which one uses very little power? (a) laptop (b) microcontroller
8. 8.🔐 Who should decide which smart devices go in a child’s room? (a) an online stranger (b) the app’s adverts (c) a parent or guardian (d) nobody at all
9. 9.Which drawing is the symbol for a diode? (a) a circle with a cross (b) a circle with M inside (c) one tall, one short bar (d) triangle against a bar
10. 10.⏱️ What does “wait 500 ms” do? (a) pauses for half a second (b) waits 500 seconds (c) turns the LED off (d) blinks 500 times
11. 11.🌐 Is a Wi-Fi doorbell camera an IoT device? (a) not an IoT device (b) an IoT device
12. 12.🔋 6 identical 1.2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
13. 13.📶 A pin that reads a push button is set as … (a) an input (b) a battery (c) an output (d) a resistor
14. 14.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
15. 15.True or false: “a door: open or shut” is a digital signal. (a) False (b) True
16. 16.Which of these is an output? (a) a turning knob (b) a keypad (c) a small display (d) a motion sensor
17. 17.🌈 A resistor has the colour bands white, orange, red. What is its value in kilo-ohms (kΩ)? =
18. 18.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
19. 19.True or false: an electric kettle mainly gives out heat. (a) False (b) True
20. 20.True or false: aluminium foil is a conductor. (a) False (b) True
21. 21.What does the Wi-Fi link do? (a) acts on a command (b) carries the data (c) shows data to you (d) stores data online
22. 22.🌈 A resistor has the colour bands red, white, orange. What is its value in kilo-ohms (kΩ)? =
23. 23.🔍 A distance sensor sends a sound pulse and hears the echo 2 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
24. 24.⏱️ loop forever { LED ON; wait 700 ms; LED OFF; wait 300 ms }
    How many milliseconds does one blink (ON + OFF) take?
25. 25.🔋 How many volts does one ordinary torch cell give? (a) 1.5 V (b) 0.5 V (c) 230 V (d) 15 V
26. 26.True or false: to reuse one password is a risky habit. (a) True (b) False
27. 27.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = R ÷ I (c) V = I × R (d) V = I + R
28. 28.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
29. 29.Which of these mainly makes sound? (a) a street light (b) a doorbell (c) a torch (d) a traffic signal
30. 30.🌐 Is a plain wall switch an IoT device? (a) not an IoT device (b) an IoT device
31. 31.📏 How many kilowatts (kW) is 4650 W? =
32. 32.What does a push button do? (a) works only while pressed (b) slides side to side (c) stays where you flip it (d) closes near a magnet
33. 33.🔍 Which is the odd one out? (a) a paper strip (b) a wooden stick (c) a graphite rod (d) a rubber eraser
34. 34.🗺️ In an input → process → output plan, is “a light level reading” the input, the process or the output? (a) process (b) input (c) output
35. 35.💡 A battery lights 4 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
36. 36.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
37. 37.Which job needs a light sensor? (a) keep an incubator warm (b) close a window in rain (c) stop a robot near walls (d) switch on lamps at dusk
38. 38.🔋 4 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)? =
39. 39.🌐 In an IoT system, which part acts on a command? (a) sensor (b) cloud server (c) phone app (d) actuator
40. 40.True or false: on an LED, the shorter leg is the cathode (−). (a) False (b) True

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