Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 365 · 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 is the odd one out? (a) read app permissions (b) change default passwords (c) tap unknown app links (d) log out of shared phones
2. 2.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a ceramic cup. Does the bulb glow? (a) Yes (b) No
3. 3.⏱️ A program says “wait 9000 ms”. How many seconds is that? =
4. 4.🔢 To plan an electronics project, which is the FIRST step? (a) test it and fix it (b) pick a problem to solve (c) draw the circuit diagram (d) build it with an adult
5. 5.Which of these saves electricity? (a) leave fridge door open (b) use daylight to read (c) leave the TV on standby (d) run fans in empty rooms
6. 6.🔢 To run one loop of a plant-watering program, what comes right after “compare with the limit”? (a) switch the pump on/off (b) read the soil sensor (c) wait a few seconds
7. 7.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
   set pin 8 HIGH
   set pin 8 LOW
   set pin 8 LOW
   Is the LED ON or OFF at the end? (a) OFF (b) ON
8. 8.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) let strangers use it (b) mute it when not in use (c) tell it your passwords (d) put it in the bathroom
9. 9.🧮 Three equal 60 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
10. 10.🔺 A current of 25 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
11. 11.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = V + R (c) I = V ÷ R (d) I = R ÷ V
12. 12.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
13. 13.⚡ What do we call a flow of electric charge through a wire? (a) sound (b) friction (c) a magnet (d) electric current
14. 14.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 50 ms }
    How many times does the LED blink in 9 seconds?
15. 15.💡 3 identical bulbs are in parallel and each bulb has its own switch on its path. 1 of the switches is OFF and the rest are ON. How many bulbs glow?
16. 16.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
17. 17.🔍 Which is the odd one out? (a) run fans in empty rooms (b) close the fridge quickly (c) leave fridge door open (d) iron one shirt at a time
18. 18.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) a single current path (c) many paths for current (d) one bulb out, all go out
19. 19.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
20. 20.Which of these is the input? (a) a button press (b) an alert on the phone (c) the fan starts (d) a buzzer beeps
21. 21.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a safety pin across the gap. Does the bulb glow? (a) Yes (b) No
22. 22.🔁 What does a variable do in a program? (a) joins two wires (b) measures light (c) stores a value (d) blinks an LED
23. 23.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
24. 24.🔺 A current of 10 mA flows when 1.2 V is joined across a resistor. What is its resistance (in ohms)?
25. 25.🧾 A 250 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
26. 26.🔺 A 1.2 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
27. 27.⚡ What does a siren mainly change electricity into? (a) heat (b) movement (c) sound (d) light
28. 28.⚡ A device works on 9 V and takes 1 A. What is its power (in watts)? =
29. 29.🌐 Each reading a sensor sends is 50 bytes. How many bytes do 180 readings take?
30. 30.🗺️ In an input → process → output plan, is “an alert on the phone” the input, the process or the output? (a) process (b) input (c) output
31. 31.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
32. 32.What does a reed switch do? (a) flips up or down (b) slides side to side (c) stays where you flip it (d) closes near a magnet
33. 33.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 53 Ω resistor? (a) orange-green-black (b) green-orange-brown (c) blue-orange-black (d) green-orange-black
34. 34.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
35. 35.Which of these is safe? (a) fly a kite near wires (b) keep drinks far away (c) touch a switch when wet (d) use a cable with cuts
36. 36.📏 Voltmeter or ammeter: which one measures voltage? (a) voltmeter (b) ammeter
37. 37.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 57000 Ω resistor? (a) green-violet-orange (b) violet-green-orange (c) green-violet-yellow (d) green-violet-red
38. 38.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) a plastic gap (d) one loose end
39. 39.🌐 Is a fitness band with app an IoT device? (a) an IoT device (b) not an IoT device
40. 40.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = I + R (c) V = I ÷ R (d) V = R ÷ I

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