Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 156 · 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.🧮 Resistors of 33 Ω, 33 Ω, 47 Ω and 470 Ω are joined in series. What is the total resistance (in ohms)?
2. 2.Which drawing is the symbol for a cell? (a) one tall, one short bar (b) a line lifted at a gap (c) a circle with a cross (d) a straight line
3. 3.🔁 total = 0
   for i = 1 to 3 { total = total + i }
   What is total at the end?
4. 4.🔐 Why install updates on IoT devices? (a) they fix security holes (b) they delete the Wi-Fi (c) they make it heavier (d) they change the colour
5. 5.🔁 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
6. 6.True or false: a plain rectangle is the symbol for a capacitor. (a) False (b) True
7. 7.What does the sensor do? (a) stores data online (b) carries the data (c) measures the real world (d) acts on a command
8. 8.Which of these mainly gives out light? (a) an electric toy car (b) a siren (c) a water heater (d) a night lamp
9. 9.📏 Which unit measures voltage? (a) watt (W) (b) ohm (Ω) (c) ampere (A) (d) volt (V)
10. 10.True or false: “an LED lights up” is the process. (a) False (b) True
11. 11.True or false: to open blinds at sunrise, use a motion sensor. (a) False (b) True
12. 12.⚠️ Is it safe to keep drinks far away? (a) safe (b) not safe
13. 13.True or false: on a cell, “the flat end” means the + (positive) end. (a) False (b) True
14. 14.🔋 A 6 V battery and two 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
15. 15.✏️ Why do engineers draw circuits with symbols? (a) quick and clear for all (b) to make it colourful (c) to hide the circuit (d) symbols are heavier
16. 16.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 900 ms }
    How many times does the LED blink in 4 seconds?
17. 17.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
18. 18.✏️ In a circuit diagram, which part is drawn as a circle with A inside? (a) motor (b) ammeter (c) battery (d) LED
19. 19.🤖 if (temperature > 34) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 10 °C. What is shown? (a) Warm (b) Hot (c) Cool
20. 20.📶 On a 5 V board, a pin set HIGH gives about … (a) 5 V (b) 230 V (c) 50 V (d) 0 V
21. 21.True or false: to install software updates is a good habit. (a) False (b) True
22. 22.💡 What does LED stand for? (a) light energy dial (b) light-emitting diode (c) low energy device (d) large electric dial
23. 23.⏱️ loop forever { LED ON; wait 600 ms; LED OFF; wait 1400 ms }
    How many times does the LED blink in 4 seconds?
24. 24.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a brass key across the gap. Does the bulb glow? (a) No (b) Yes
25. 25.True or false: on an LED, the round-side leg is the cathode (−). (a) True (b) False
26. 26.🔍 Which is the odd one out? (a) stay away from pylons (b) keep drinks far away (c) use mains for a project (d) take cells out after use
27. 27.🔺 A current of 25 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
28. 28.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) diode (b) bulb (c) LED (d) capacitor
29. 29.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) gets smaller (c) gets bigger (d) stays the same
30. 30.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) none (c) both of them (d) only one
31. 31.🔍 Which is the odd one out? (a) use old filament bulbs (b) leave fridge door open (c) close the fridge quickly (d) iron one shirt at a time
32. 32.🔐 Which is the strongest password for a home smart camera? (a) 123456 (b) Tiger#Lamp42!Moon (c) admin (d) password
33. 33.Which drawing is the symbol for a voltmeter? (a) a straight line (b) a circle with V inside (c) a circle with A inside (d) a plain rectangle
34. 34.⚙️ Which actuator would you use to beep an alarm? (a) a servo motor (b) a buzzer (c) a display (d) an LED
35. 35.💡 Why is house wiring done in parallel? (a) to save copper only (b) to make bulbs dim (c) each gets full voltage (d) so all go off together
36. 36.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 50 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
37. 37.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
38. 38.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 0 % (c) 5 % (d) 50 %
39. 39.💡 4 identical bulbs are joined in series with a 10 V battery (ideal wires). How many volts does each bulb get? =
40. 40.💡 An LED is joined to a 5 V battery through a 330 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) does not light (b) lights up (c) may burn out

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