Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 487 · 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.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 1000 (c) 60 (d) 10
2. 2.What does a diode do? (a) is a resistance knob (b) glows using little power (c) lets current go one way (d) limits the current
3. 3.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = R ÷ V (c) I = V + R (d) I = V ÷ R
4. 4.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are ON (b) never (c) when either is ON (d) only when both are OFF
5. 5.True or false: “a button: pressed or not” is a digital signal. (a) False (b) True
6. 6.⏱️ What does “wait 500 ms” do? (a) blinks 500 times (b) waits 500 seconds (c) turns the LED off (d) pauses for half a second
7. 7.🔋 A 3 V battery and one 1.5 V cell are joined in series, all facing the same way. What is the total voltage (in volts)? =
8. 8.🔺 A 9.4 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
9. 9.🔍 Which is the odd one out? (a) a torch (b) a traffic signal (c) a buzzer (d) a street light
10. 10.🔘 A cell and a bulb are joined to 3 side-by-side paths with one switch on each path — A, B and C (parallel). A is OFF, B is ON and C is ON. Does the bulb glow? (a) Yes (b) No
11. 11.True or false: power is measured in watts (W). (a) False (b) True
12. 12.⏱️ A program says “wait 7500 ms”. How many seconds is that? =
13. 13.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the process (b) the input (c) the battery (d) the output
14. 14.✏️ In a circuit diagram, which part is drawn as two equal parallel lines? (a) cell (b) ammeter (c) capacitor (d) junction
15. 15.🔌 Which part of a screwdriver should an electrician hold? (a) the bare end (b) the steel shaft (c) the metal tip (d) the plastic handle
16. 16.⚠️ About how many volts do home sockets in India supply? (a) 230 V (b) 9 V (c) 1.5 V (d) 12 V
17. 17.⚠️ Is it safe to build with an adult near? (a) safe (b) not safe
18. 18.🤖 if (temperature > 37) { show “Hot” } else if (temperature > 22) { show “Warm” } else { show “Cool” }
    The temperature is 44 °C. What is shown? (a) Cool (b) Hot (c) Warm
19. 19.Which of these is a conductor? (a) a cotton thread (b) a plastic straw (c) a steel coin (d) a ceramic cup
20. 20.True or false: “a light level reading” is the input. (a) True (b) False
21. 21.💡 2 identical bulbs are joined in series with a 5 V battery (ideal wires). How many volts does each bulb get? =
22. 22.True or false: a torch mainly gives out heat. (a) True (b) False
23. 23.What does an LDR do? (a) has coloured bands (b) is a resistance knob (c) glows using little power (d) senses how bright it is
24. 24.📶 A pin set LOW gives about … (a) 5 V (b) 1.5 V (c) 0 V (d) 9 V
25. 25.🔺 A current of 2 A flows when 30 V is joined across a resistor. What is its resistance (in ohms)?
26. 26.Which drawing is the symbol for an LED? (a) triangle, bar and arrows (b) a long and a short line (c) two or more cell symbols (d) a dot where wires meet
27. 27.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they explode (b) they all go out (c) they keep glowing (d) they get dimmer
28. 28.Which drawing is the symbol for a capacitor? (a) a straight line (b) triangle against a bar (c) a line lifted at a gap (d) two equal parallel lines
29. 29.Which job needs a sound sensor? (a) stop a robot near walls (b) keep an incubator warm (c) water a dry plant (d) measure classroom noise
30. 30.What does the phone app do? (a) carries the data (b) acts on a command (c) shows data to you (d) stores data online
31. 31.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
32. 32.What does a toggle switch do? (a) slides side to side (b) flips up or down (c) springs back when let go (d) closes when tipped over
33. 33.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 8 LOW
    set pin 7 LOW
    set pin 8 LOW
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
34. 34.🌈 A resistor has the colour bands brown, blue, black. What is its value (in ohms)?
35. 35.Which of these mainly gives out light? (a) an electric drill (b) a street light (c) an exhaust fan (d) a table fan
36. 36.⚡ Which formula gives electric power? (a) P = V + I (b) P = V × I (c) P = V ÷ I (d) P = I ÷ V
37. 37.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. Does bulb 2 glow? (a) Yes (b) No
38. 38.True or false: a buzzer makes a beeping sound. (a) False (b) True
39. 39.🔁 What does “count = count + 1” do? (a) takes 1 away (b) adds 1 to count (c) sets count to 1 (d) prints 1
40. 40.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed

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