Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 983 · 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 72 W device works on 24 V. What current does it take (in amperes)? =
2. 2.🧩 A capacitor in a circuit can … (a) spin a wheel (b) make light (c) store charge briefly (d) measure heat
3. 3.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
4. 4.⚠️ Is it safe to poke things in a socket? (a) safe (b) not safe
5. 5.⚡ What do we call a flow of electric charge through a wire? (a) friction (b) electric current (c) a magnet (d) sound
6. 6.True or false: to accept every permission is a good habit. (a) True (b) False
7. 7.🔁 total = 0
   for i = 1 to 9 { total = total + i }
   What is total at the end?
8. 8.🧩 Which component turns a fan or wheels? (a) motor (b) buzzer (c) resistor (d) transistor
9. 9.🔁 x = 3
   repeat 4 times { x = x × 2 }
   What is x at the end?
10. 10.🔍 A distance sensor sends a sound pulse and hears the echo 10 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
11. 11.🧮 A 10 Ω resistor is joined in series with two equal 470 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
12. 12.🔁 repeat 2 times { repeat 2 times { beep } }
    How many beeps are there?
13. 13.🔁 count = 1
    repeat 5 times { count = count + 6 }
    What is count at the end?
14. 14.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) not joined (c) in series (d) by Wi-Fi
15. 15.🔺 A current of 20 mA flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
16. 16.🔋 Does a generator give electricity or use electricity? (a) uses electricity (b) gives electricity
17. 17.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) an open circuit (d) a series circuit
18. 18.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
19. 19.✏️ In a cell symbol, which line is the + terminal? (a) both lines (b) neither line (c) the shorter line (d) the longer line
20. 20.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 1600 Ω resistor? (a) brown-blue-brown (b) brown-blue-red (c) brown-blue-orange (d) blue-brown-red
21. 21.⚡ A cell changes stored chemical energy into which kind of energy? (a) wind energy (b) sound energy (c) nuclear energy (d) electrical energy
22. 22.🔺 A current of 25 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
23. 23.🔐 Is it a good or a risky habit to tap unknown app links? (a) risky habit (b) good habit
24. 24.🧮 A 33 Ω resistor is joined in series with two equal 100 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
25. 25.🔋 How many 2 V cells must be joined in series to give 16 V?
26. 26.What does a transistor do? (a) makes a beeping sound (b) is a resistance knob (c) stores a little charge (d) boosts a small signal
27. 27.🔁 x = 5
    repeat 1 time { x = x × 2 }
    What is x at the end?
28. 28.💡 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
29. 29.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a plastic ruler across the gap. Does the bulb glow? (a) Yes (b) No
30. 30.🔌 Is an LED an input or an output for a microcontroller? (a) output (b) input
31. 31.🌐 Is a smart energy meter an IoT device? (a) not an IoT device (b) an IoT device
32. 32.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) to save copper only (c) so all go off together (d) each gets full voltage
33. 33.True or false: to fly kites in open fields is safe. (a) False (b) True
34. 34.🔋 Does a washing machine give electricity or use electricity? (a) uses electricity (b) gives electricity
35. 35.🔋 What should you do with used-up cells? (a) cut them open (b) give them for recycling (c) bury them in soil (d) throw them in a fire
36. 36.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
37. 37.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
    The temperature is 22 °C. What is shown? (a) Warm (b) Hot (c) Cool
38. 38.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
39. 39.🔺 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
40. 40.🧩 Which component has coloured bands? (a) motor (b) LED (c) resistor (d) fuse

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