Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 916 · 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: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
2. 2.Which of these is true of a series circuit? (a) one out, the rest glow (b) many paths for current (c) used in house wiring (d) bulbs share the voltage
3. 3.🔺 A current of 0.25 A flows when 3.75 V is joined across a resistor. What is its resistance (in ohms)?
4. 4.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
5. 5.Which of these is not safe? (a) fly kites in open fields (b) stay away from pylons (c) stop if a part gets hot (d) touch a switch when wet
6. 6.📏 How many ohms (Ω) is 0.6 kΩ?
7. 7.Which of these is a conductor? (a) a glass marble (b) a rubber band (c) a wooden stick (d) a steel coin
8. 8.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
9. 9.💡 A red LED uses 2 V and should get 10 mA. It runs from a 9 V supply. What resistor (in ohms) is needed in series?
10. 10.⚡ Which formula gives electric power? (a) P = V × I (b) P = V + I (c) P = V ÷ I (d) P = I ÷ V
11. 11.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 60 (c) 10 (d) 1000
12. 12.💡 2 identical bulbs are in parallel and each one takes 0.2 A. What total current (in amperes) comes from the battery? =
13. 13.True or false: “one out, the rest glow” is true of a parallel circuit. (a) True (b) False
14. 14.True or false: “the room temperature” is an analog signal. (a) True (b) False
15. 15.🔋 4 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
16. 16.🧮 A 2 V battery is joined to 8 Ω and 12 Ω resistors in series. What current flows (in amperes)? =
17. 17.🔺 A current of 20 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
18. 18.True or false: a toy robot has no microcontroller inside. (a) False (b) True
19. 19.🔺 A current of 3 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
20. 20.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) one loose end (d) a plastic gap
21. 21.🔁 repeat 6 times { repeat 5 times { beep } }
    How many beeps are there?
22. 22.📏 How many kilo-ohms (kΩ) is 2200 Ω? =
23. 23.🤖 if (distance < 30) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 29 cm. What happens? (a) buzzer beeps (b) buzzer is silent
24. 24.🔘 A cell, a bulb and switches A, B and C are joined one after another in a single loop (series). A is ON, B is OFF and C is OFF. Does the bulb glow? (a) Yes (b) No
25. 25.🌈 A resistor has the colour bands blue, blue, yellow. What is its value in kilo-ohms (kΩ)? =
26. 26.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) waits 500 seconds (c) pauses for half a second (d) blinks 500 times
27. 27.🔍 Which is the odd one out? (a) tap unknown app links (b) cover unused cameras (c) share the Wi-Fi key (d) keep factory passwords
28. 28.🔺 A 2 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
29. 29.🔌 Is a buzzer an input or an output for a microcontroller? (a) output (b) input
30. 30.📶 A pin that reads a push button is set as … (a) a battery (b) an input (c) an output (d) a resistor
31. 31.🔁 What does a variable do in a program? (a) measures light (b) joins two wires (c) blinks an LED (d) stores a value
32. 32.Which of these is measured in volts (V)? (a) the flow of charge (b) current (c) voltage (d) how much a part resists
33. 33.Which of these is an input? (a) a small display (b) a speaker (c) a servo motor (d) a turning knob
34. 34.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
35. 35.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) stay the same (c) zero (d) smaller
36. 36.Which job needs a display? (a) turn to an exact angle (b) beep an alarm (c) show the temperature (d) spin a robot’s wheels
37. 37.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
38. 38.Which drawing is the symbol for a voltmeter? (a) a plain rectangle (b) two equal parallel lines (c) a circle with V inside (d) one tall, one short bar
39. 39.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 8 HIGH
    set pin 7 LOW
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
40. 40.💡 2 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?

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