Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 552 · 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 mainly makes movement? (a) a tube light (b) an electric iron (c) a mixer grinder (d) a traffic signal
2. 2.🌈 A resistor has the colour bands yellow, white, red. What is its value in kilo-ohms (kΩ)? =
3. 3.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) series (b) parallel
4. 4.🔌 A gap of dry air between two wires acts as … (a) a cell (b) a switch that is ON (c) a conductor (d) an insulator
5. 5.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 100 ms }
   How many times does the LED blink in 10 seconds?
6. 6.🔍 A distance sensor sends a sound pulse and hears the echo 16 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
7. 7.🔺 In the V-I-R triangle, how do we find R? (a) R = V + I (b) R = I ÷ V (c) R = V × I (d) R = V ÷ I
8. 8.True or false: to keep an incubator warm, use a distance sensor. (a) True (b) False
9. 9.🔋 How many 2 V cells must be joined in series to give 8 V?
10. 10.⚡ A 4.5 W device works on 9 V. What current does it take (in amperes)? =
11. 11.Which of these saves electricity? (a) leave fridge door open (b) set the AC to 24 °C (c) run fans in empty rooms (d) use old filament bulbs
12. 12.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 50 % (c) 0 % (d) 5 %
13. 13.🌐 What does IoT stand for? (a) Input of Tools (b) Internet of Talk (c) Inside of Toys (d) Internet of Things
14. 14.🔺 A current of 1.5 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
15. 15.🌐 Each reading a sensor sends is 50 bytes. How many bytes do 70 readings take?
16. 16.🌐 Is a paper calendar an IoT device? (a) not an IoT device (b) an IoT device
17. 17.🗺️ In an input → process → output plan, is “the fan starts” the input, the process or the output? (a) output (b) process (c) input
18. 18.🔌 Is a light sensor an input or an output for a microcontroller? (a) input (b) output
19. 19.🧮 Two equal 330 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
20. 20.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) False (b) True
21. 21.🔺 A 3.75 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
22. 22.Which of these is safe? (a) throw cells in a fire (b) use small battery cells (c) fly a kite near wires (d) touch a fallen wire
23. 23.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) bigger (c) zero (d) stay the same
24. 24.⚠️ Is it safe to climb an electric pole? (a) safe (b) not safe
25. 25.🔁 repeat 2 times { repeat 5 times { beep } }
    How many beeps are there?
26. 26.🔺 A 10 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
27. 27.True or false: to water a dry plant, use a soil moisture sensor. (a) False (b) True
28. 28.📏 Voltmeter or ammeter: which one is joined across a part? (a) ammeter (b) voltmeter
29. 29.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 10 (c) 1000 (d) 60
30. 30.🧩 A capacitor in a circuit can … (a) make light (b) store charge briefly (c) spin a wheel (d) measure heat
31. 31.Which of these is true of a parallel circuit? (a) many paths for current (b) a single current path (c) bulbs share the voltage (d) a break stops every bulb
32. 32.Which of these is an insulator? (a) a brass key (b) a ceramic cup (c) a copper wire (d) a safety pin
33. 33.📶 On a 5 V board, a pin set HIGH gives about … (a) 0 V (b) 230 V (c) 5 V (d) 50 V
34. 34.True or false: a washing machine usually has a microcontroller inside. (a) False (b) True
35. 35.🤖 “if (A AND B)” is true when … (a) both are false (b) only A is true (c) both A and B are true (d) only B is true
36. 36.Which job needs a motion sensor? (a) water a dry plant (b) warn of a gas leak (c) keep an incubator warm (d) spot someone walking in
37. 37.💡 An LED is joined to a 3 V battery through a 1000 Ω resistor; its long leg goes to the − side and its short leg to the + side. What happens? (a) may burn out (b) lights up (c) does not light
38. 38.🔺 A current of 0.5 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
39. 39.🔋 8 identical 1.5 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
40. 40.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a dry cork across the gap. Does the bulb glow? (a) Yes (b) No

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