Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 604 · 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 happens if an LED is put in backwards? (a) it makes a sound (b) it does not light (c) it lights brighter (d) it changes colour
2. 2.🔍 Which is the odd one out? (a) compare with a limit (b) count button presses (c) a temperature reading (d) check if temp > 30
3. 3.🔺 A current of 0.1 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
4. 4.True or false: a safety pin is an insulator. (a) True (b) False
5. 5.🔺 A current of 1 A flows when 8 V is joined across a resistor. What is its resistance (in ohms)?
6. 6.🔋 Does a battery give electricity or use electricity? (a) gives electricity (b) uses electricity
7. 7.🤖 “if (A AND B)” is true when … (a) both are false (b) only A is true (c) only B is true (d) both A and B are true
8. 8.🔺 A current of 2.5 A flows when 50 V is joined across a resistor. What is its resistance (in ohms)?
9. 9.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
10. 10.🔁 What does a variable do in a program? (a) blinks an LED (b) stores a value (c) measures light (d) joins two wires
11. 11.🔦 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 coin. Does the bulb glow? (a) No (b) Yes
12. 12.🔌 Which part of a screwdriver should an electrician hold? (a) the bare end (b) the plastic handle (c) the steel shaft (d) the metal tip
13. 13.🌈 In the resistor colour code, which number does brown stand for?
14. 14.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is ON, B is ON and C is OFF. Does the bulb glow? (a) No (b) Yes
15. 15.True or false: “a light level reading” is the output. (a) False (b) True
16. 16.True or false: a circle with an X in it is the symbol for a cell. (a) False (b) True
17. 17.True or false: a reed switch flips up or down. (a) True (b) False
18. 18.💡 A battery lights 5 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
19. 19.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 340 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
20. 20.Which drawing is the symbol for a voltmeter? (a) many long-short pairs (b) a small empty box (c) a dot where wires meet (d) a circle with V inside
21. 21.⚡ A device works on 1.5 V and takes 1.5 A. What is its power (in watts)? =
22. 22.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) + (positive) (b) − (negative)
23. 23.✏️ In a circuit diagram, which part is drawn as a circle with an X in it? (a) ammeter (b) battery (c) bulb (d) LED
24. 24.Which of these is safe? (a) touch a switch when wet (b) stay away from pylons (c) use a cable with cuts (d) throw cells in a fire
25. 25.🌈 A resistor has the colour bands brown, blue, red. What is its value (in ohms)?
26. 26.🔌 Is a motor an input or an output for a microcontroller? (a) input (b) output
27. 27.True or false: to leave fridge door open saves electricity. (a) True (b) False
28. 28.True or false: “a break stops every bulb” is true of a series circuit. (a) False (b) True
29. 29.🔗 Series or parallel circuit: “one out, the rest glow”? (a) parallel (b) series
30. 30.What does a slide switch do? (a) slides side to side (b) closes when tipped over (c) works only while pressed (d) flips up or down
31. 31.Which of these has no microcontroller inside? (a) a microwave oven (b) a toy robot (c) a smart watch (d) a hand pump
32. 32.True or false: a tilt switch works only while pressed. (a) False (b) True
33. 33.🌈 A resistor has the colour bands yellow, yellow, black. What is its value (in ohms)?
34. 34.True or false: to use small battery cells is not safe. (a) False (b) True
35. 35.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) waits 500 seconds (c) blinks 500 times (d) pauses for half a second
36. 36.🔺 A current of 20 mA flows when 2.4 V is joined across a resistor. What is its resistance (in ohms)?
37. 37.🔍 Which is the odd one out? (a) a graphite rod (b) a steel spoon (c) a cotton thread (d) a copper wire
38. 38.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a wire has come loose
39. 39.💡 Why is house wiring done in parallel? (a) so all go off together (b) to make bulbs dim (c) to save copper only (d) each gets full voltage
40. 40.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 0 % (c) 5 % (d) 50 %

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