Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 224 · 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 of these is safe? (a) fly kites in open fields (b) throw cells in a fire (c) touch a switch when wet (d) open a phone charger
2. 2.⚡ What does a school bell mainly change electricity into? (a) sound (b) light (c) movement (d) heat
3. 3.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) zero (c) bigger (d) smaller
4. 4.Which of these mainly makes movement? (a) a toaster (b) a school bell (c) an electric drill (d) a siren
5. 5.True or false: on a cell, “usually the red wire” means the + (positive) end. (a) True (b) False
6. 6.🔺 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
7. 7.🔺 A current of 1.5 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
8. 8.True or false: the push of a cell is measured in amperes (A). (a) True (b) False
9. 9.⏱️ A program says “wait 250 ms”. How many seconds is that? =
10. 10.⏱️ 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
11. 11.True or false: two or more cell symbols is the symbol for a diode. (a) True (b) False
12. 12.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) not joined (b) in series (c) in parallel (d) by Wi-Fi
13. 13.What does a capacitor do? (a) glows using little power (b) has coloured bands (c) smooths a wobbly supply (d) blows if current is high
14. 14.Which of these is safe? (a) open a phone charger (b) fly a kite near wires (c) build with an adult near (d) poke things in a socket
15. 15.🧮 Resistors of 20 Ω, 50 Ω, 50 Ω and 470 Ω are joined in series. What is the total resistance (in ohms)?
16. 16.⚠️ Who should be with you when you build a circuit? (a) a trusted adult (b) a stranger online (c) nobody (d) a younger child
17. 17.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
18. 18.🤖 if (sound > 60) { red LED ON } else { green LED ON }
    The sound sensor reads 65. What happens? (a) red LED ON (b) green LED ON
19. 19.🔁 count = 6
    repeat 8 times { count = count + 4 }
    What is count at the end?
20. 20.💡 3 identical bulbs are joined in parallel across a 6 V battery (ideal wires). How many volts does each bulb get? =
21. 21.True or false: a slide switch flips up or down. (a) True (b) False
22. 22.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a series circuit (d) a full circuit
23. 23.🔺 A 2 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
24. 24.⚠️ Why must we never touch switches with wet hands? (a) water makes it cold (b) it spoils the paint (c) it is just untidy (d) water carries current
25. 25.🧩 Which part changes electrical energy into sound? (a) a resistor (b) a capacitor (c) a buzzer (d) a diode
26. 26.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 520 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
27. 27.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I × R (c) V = I + R (d) V = I ÷ R
28. 28.🔘 When a switch is ON, the circuit is … (a) cut (b) broken (c) open (d) closed
29. 29.🧭 Which part of a microcontroller board brings power and code? (a) the pins (b) the main chip (c) the USB port (d) the reset button
30. 30.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a short circuit (b) an open circuit (c) a parallel circuit (d) a safe circuit
31. 31.True or false: to leave the TV on standby wastes electricity. (a) True (b) False
32. 32.🔍 Which is the odd one out? (a) switch off empty rooms (b) leave the TV on standby (c) close the fridge quickly (d) set the AC to 24 °C
33. 33.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 590 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
34. 34.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) ammeter (b) LED (c) diode (d) wire
35. 35.🔁 repeat 4 times { repeat 3 times { beep } }
    How many beeps are there?
36. 36.What does a reed switch do? (a) closes when tipped over (b) flips up or down (c) closes near a magnet (d) stays where you flip it
37. 37.🌐 How does a home IoT device usually send its data to the app? (a) over Wi-Fi (b) by post (c) by shouting (d) through a candle
38. 38.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) switch (b) resistor (c) motor (d) capacitor
39. 39.Which job needs a buzzer? (a) open a gate to 90° (b) turn to an exact angle (c) show a status light (d) beep an alarm
40. 40.Which job needs a sound sensor? (a) measure classroom noise (b) open blinds at sunrise (c) warn of a gas leak (d) spot someone walking in

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