Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 864 · 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.🔘 A bulb and a cell are joined through 5 switches on 5 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
2. 2.True or false: to share only needed data is a risky habit. (a) True (b) False
3. 3.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 6 is taken out of its holder. How many bulbs glow?
4. 4.🔦 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) No (b) Yes
5. 5.🗺️ In an input → process → output plan, is “decide if soil is dry” the input, the process or the output? (a) process (b) input (c) output
6. 6.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 57 Ω resistor? (a) green-violet-black (b) violet-green-black (c) green-violet-brown (d) blue-violet-black
7. 7.🔍 Which is the odd one out? (a) a motion sensor signal (b) a temperature reading (c) a button press (d) check if temp > 30
8. 8.⚠️ Is it safe to use small battery cells? (a) safe (b) not safe
9. 9.💡 In a series circuit, how many paths does the current have? (a) two (b) one for each bulb (c) one (d) none
10. 10.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a rubber eraser. Does the bulb glow? (a) Yes (b) No
11. 11.🔘 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 OFF, B is ON and C is OFF. Does the bulb glow? (a) No (b) Yes
12. 12.⏱️ What does “wait 500 ms” do? (a) blinks 500 times (b) pauses for half a second (c) turns the LED off (d) waits 500 seconds
13. 13.🤖 Does a microwave oven usually have a microcontroller inside? (a) No (b) Yes
14. 14.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) one loose end (d) a complete loop
15. 15.True or false: current is measured in volts (V). (a) True (b) False
16. 16.✏️ In a circuit diagram, which part is drawn as a line lifted at a gap? (a) battery (b) ammeter (c) switch (d) wire
17. 17.🔋 5 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
18. 18.🧩 Which component blows if current is high? (a) fuse (b) transistor (c) motor (d) LDR
19. 19.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a closed circuit (c) an open circuit (d) a full circuit
20. 20.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
21. 21.🔋 Cells joined + to − in a row (series) give … (a) a bigger voltage (b) no voltage (c) a smaller voltage (d) the same voltage
22. 22.🔺 A current of 25 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
23. 23.🔍 Which is the odd one out? (a) leave fridge door open (b) leave the TV on standby (c) unplug idle chargers (d) iron one shirt at a time
24. 24.⏱️ repeat 3 times { buzzer ON; wait 300 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
25. 25.True or false: a circle with M inside is the symbol for a motor. (a) False (b) True
26. 26.🔺 A current of 40 mA flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
27. 27.🔌 Is a copper wire a conductor or an insulator? (a) an insulator (b) a conductor
28. 28.Which of these is measured in ohms (Ω)? (a) how much a part resists (b) the flow of charge (c) the push of a cell (d) energy used each second
29. 29.Which of these is safe? (a) touch a switch when wet (b) use mains for a project (c) fly a kite near wires (d) stay away from pylons
30. 30.True or false: to run fans in empty rooms wastes electricity. (a) False (b) True
31. 31.✏️ In a circuit diagram, which part is drawn as triangle, bar and arrows? (a) ammeter (b) LED (c) motor (d) battery
32. 32.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) prints 1 (c) adds 1 to count (d) takes 1 away
33. 33.What does the cloud server do? (a) acts on a command (b) stores data online (c) measures the real world (d) shows data to you
34. 34.🔋 Does a washing machine give electricity or use electricity? (a) uses electricity (b) gives electricity
35. 35.🧮 Two equal 220 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
36. 36.🌈 In the resistor colour code, which number does grey stand for?
37. 37.💡 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
38. 38.🔌 Is an iron nail a conductor or an insulator? (a) an insulator (b) a conductor
39. 39.🌈 A resistor has the colour bands red, blue, black. What is its value (in ohms)?
40. 40.🔍 Which is the odd one out? (a) stop if a part gets hot (b) touch a switch when wet (c) build with an adult near (d) keep drinks far away

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