Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 853 · 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.True or false: to fly kites in open fields is not safe. (a) False (b) True
2. 2.True or false: “bulbs share the voltage” is true of a series circuit. (a) True (b) False
3. 3.🔍 Which is the odd one out? (a) climb an electric pole (b) take cells out after use (c) touch a fallen wire (d) use a cable with cuts
4. 4.⏱️ loop forever { LED ON; wait 1800 ms; LED OFF; wait 200 ms }
   How many times does the LED blink in 10 seconds?
5. 5.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is ON, B is OFF, C is ON and D is OFF. Does the bulb glow? (a) Yes (b) No
6. 6.🔋 A 3 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
7. 7.🔺 A current of 0.5 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
8. 8.Which of these is true of a parallel circuit? (a) bulbs share the voltage (b) a break stops every bulb (c) one out, the rest glow (d) one bulb out, all go out
9. 9.🤖 if (temperature > 38) { show “Hot” } else if (temperature > 19) { show “Warm” } else { show “Cool” }
   The temperature is 40 °C. What is shown? (a) Warm (b) Hot (c) Cool
10. 10.⚡ A 0.15 W device works on 1.5 V. What current does it take (in amperes)? =
11. 11.🔍 Which is the odd one out? (a) a light sensor (b) a buzzer (c) a turning knob (d) a sound sensor
12. 12.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
13. 13.🔍 Which is the odd one out? (a) a safety pin (b) a wooden stick (c) a copper wire (d) a steel coin
14. 14.True or false: a resistor has coloured bands. (a) False (b) True
15. 15.⚠️ Is it safe to stop if a part gets hot? (a) not safe (b) safe
16. 16.🔐 Is it a good or a risky habit to share camera links? (a) good habit (b) risky habit
17. 17.🔍 Which is the odd one out? (a) a Wi-Fi doorbell camera (b) a Wi-Fi weather station (c) a plain table fan (d) an app-controlled bulb
18. 18.🔺 In the V-I-R triangle, how do we find R? (a) R = I ÷ V (b) R = V × I (c) R = V + I (d) R = V ÷ I
19. 19.🧮 A 3.25 V battery is joined to 10 Ω and 3 Ω resistors in series. What current flows (in amperes)? =
20. 20.✏️ In a cell symbol, which line is the + terminal? (a) neither line (b) the shorter line (c) the longer line (d) both lines
21. 21.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 140 Ω resistor? (a) brown-yellow-red (b) brown-yellow-brown (c) yellow-brown-brown (d) brown-yellow-black
22. 22.🔍 Which is the odd one out? (a) read app permissions (b) ignore update messages (c) cover unused cameras (d) change default passwords
23. 23.⚙️ What is an actuator? (a) a battery (b) a program (c) an output that acts (d) a sensor
24. 24.💡 4 identical bulbs are joined in parallel across a 6 V battery (ideal wires). How many volts does each bulb get? =
25. 25.Which of these mainly makes sound? (a) an electric toy car (b) a room heater (c) a buzzer (d) a rice cooker
26. 26.Which job needs a motor? (a) beep an alarm (b) spin a robot’s wheels (c) show the temperature (d) open a gate to 90°
27. 27.🧩 Which component senses how hot it is? (a) LED (b) motor (c) LDR (d) thermistor
28. 28.True or false: “an LED lights up” is the output. (a) False (b) True
29. 29.🔍 Which is the odd one out? (a) an electric toy car (b) an electric drill (c) a mixer grinder (d) a night lamp
30. 30.🔺 A current of 10 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
31. 31.🔍 Which is the odd one out? (a) an app-controlled bulb (b) a paper calendar (c) a smart energy meter (d) a Wi-Fi doorbell camera
32. 32.🧩 A capacitor in a circuit can … (a) measure heat (b) make light (c) spin a wheel (d) store charge briefly
33. 33.Which of these is a risky habit? (a) cover unused cameras (b) share only needed data (c) set a strong password (d) share camera links
34. 34.⏱️ What does “wait 500 ms” do? (a) blinks 500 times (b) pauses for half a second (c) waits 500 seconds (d) turns the LED off
35. 35.🤖 if (temperature > 30) { fan ON } else { fan OFF }
    The temperature sensor reads 31 °C. What happens? (a) fan OFF (b) fan ON
36. 36.⏱️ loop forever { LED ON; wait 400 ms; LED OFF; wait 650 ms }
    How many milliseconds does one blink (ON + OFF) take?
37. 37.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a graphite rod across the gap. Does the bulb glow? (a) No (b) Yes
38. 38.🗺️ In an input → process → output plan, is “a button press” the input, the process or the output? (a) output (b) input (c) process
39. 39.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a plastic straw across the gap. Does the bulb glow? (a) No (b) Yes
40. 40.🔁 What does “count = count + 1” do? (a) adds 1 to count (b) sets count to 1 (c) prints 1 (d) takes 1 away

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