Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 98 · 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.✏️ In a cell symbol, which line is the + terminal? (a) both lines (b) the shorter line (c) the longer line (d) neither line
2. 2.True or false: to keep drinks far away is safe. (a) True (b) False
3. 3.True or false: the voltmeter measures current. (a) False (b) True
4. 4.🔁 count = 3
   while (count < 17) { count = count + 2 }
   How many times does the loop run?
5. 5.Which of these is a risky habit? (a) set up with a parent (b) share camera links (c) log out of shared phones (d) share only needed data
6. 6.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) − (negative) (b) + (positive)
7. 7.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
8. 8.🔌 Is a small display an input or an output for a microcontroller? (a) input (b) output
9. 9.🔋 Does a water pump give electricity or use electricity? (a) uses electricity (b) gives electricity
10. 10.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
11. 11.🔺 In the V-I-R triangle, how do we find V? (a) V = I + R (b) V = I ÷ R (c) V = R ÷ I (d) V = I × R
12. 12.🤖 “if (A AND B)” is true when … (a) both A and B are true (b) only A is true (c) only B is true (d) both are false
13. 13.🌐 In an IoT system, which part reads values, decides? (a) actuator (b) sensor (c) Wi-Fi (d) microcontroller
14. 14.🧩 Which part changes electrical energy into movement? (a) an LED (b) a motor (c) a fuse (d) a resistor
15. 15.🔺 A current of 10 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
16. 16.Which of these is an IoT device? (a) a wind-up clock (b) a battery torch (c) a plain table fan (d) a Wi-Fi weather station
17. 17.🧩 Which component beeps for an alarm? (a) transistor (b) motor (c) potentiometer (d) buzzer
18. 18.True or false: the flow of charge is measured in amperes (A). (a) True (b) False
19. 19.🔐 Is it a good or a risky habit to read app permissions? (a) risky habit (b) good habit
20. 20.🔍 Which sensor would you use to measure classroom noise? (a) a sound sensor (b) a soil moisture sensor (c) a gas sensor (d) a motion sensor
21. 21.⏱️ How many milliseconds is a wait of 0.3 seconds?
22. 22.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 6200 Ω resistor? (a) blue-red-orange (b) red-blue-red (c) blue-red-red (d) blue-red-brown
23. 23.💡 A red LED uses 2 V and should get 20 mA. It runs from a 6 V supply. What resistor (in ohms) is needed in series?
24. 24.💡 In a series circuit, how many paths does the current have? (a) one (b) one for each bulb (c) none (d) two
25. 25.True or false: a push button closes when tipped over. (a) False (b) True
26. 26.⚡ A device works on 6 V and takes 0.25 A. What is its power (in watts)? =
27. 27.True or false: a dry cork is a conductor. (a) False (b) True
28. 28.⚡ Which tiny particles drift along a metal wire to carry the current? (a) dust particles (b) water drops (c) electrons (d) photons
29. 29.🔁 What does “count = count + 1” do? (a) adds 1 to count (b) sets count to 1 (c) takes 1 away (d) prints 1
30. 30.Which of these saves electricity? (a) use old filament bulbs (b) leave fridge door open (c) leave the TV on standby (d) use LED lamps
31. 31.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
32. 32.⚡ A device works on 3 V and takes 0.2 A. What is its power (in watts)? =
33. 33.Which drawing is the symbol for a bulb? (a) two or more cell symbols (b) two equal parallel lines (c) a circle with an X in it (d) a straight line
34. 34.Which of these is measured in amperes (A)? (a) resistance (b) energy used each second (c) current (d) voltage
35. 35.Which drawing is the symbol for a cell? (a) a circle with M inside (b) a circle with a cross (c) a circle with V inside (d) a long and a short line
36. 36.🔁 repeat 2 times { repeat 4 times { beep } }
    How many beeps are there?
37. 37.🏠 Which is a smart-home example? (a) lights on from an app (b) a printed map (c) a hand fan (d) a candle in a jar
38. 38.True or false: on an LED, the leg by the flat edge is the cathode (−). (a) False (b) True
39. 39.🌐 Each reading a sensor sends is 25 bytes. How many bytes do 40 readings take?
40. 40.Which of these is a conductor? (a) a plastic straw (b) a cotton thread (c) aluminium foil (d) a ceramic cup

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