Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 865 · 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.🌐 A weather station sends one reading every 10 seconds. How many readings does it send in 9 minutes?
2. 2.Which drawing is the symbol for an LED? (a) many long-short pairs (b) two or more cell symbols (c) two equal parallel lines (d) triangle, bar and arrows
3. 3.🔐 Is it a good or a risky habit to ignore update messages? (a) good habit (b) risky habit
4. 4.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the process (b) the battery (c) the output (d) the input
5. 5.🔍 Which is the odd one out? (a) a glass marble (b) a wooden stick (c) a steel spoon (d) a rubber band
6. 6.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 270 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
7. 7.True or false: “one out, the rest glow” is true of a parallel circuit. (a) True (b) False
8. 8.⚠️ Is it safe to stop if a part gets hot? (a) safe (b) not safe
9. 9.🔁 repeat 3 times { repeat 4 times { beep } }
   How many beeps are there?
10. 10.Which job needs a servo motor? (a) turn to an exact angle (b) show a status light (c) spin a robot’s wheels (d) move water to plants
11. 11.⚠️ Is it safe to poke things in a socket? (a) not safe (b) safe
12. 12.True or false: a circle with V inside is the symbol for a voltmeter. (a) True (b) False
13. 13.✏️ In a circuit diagram, which part is drawn as a dot where wires meet? (a) resistor (b) junction (c) wire (d) LED
14. 14.🔍 A distance sensor sends a sound pulse and hears the echo 8 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
15. 15.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
16. 16.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
17. 17.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a glass marble. Does the bulb glow? (a) No (b) Yes
18. 18.🔘 A bulb and a cell are joined through 4 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
19. 19.💡 A blue LED uses 3 V and should get 10 mA. It runs from a 9 V supply. What resistor (in ohms) is needed in series?
20. 20.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) let strangers use it (b) tell it your passwords (c) mute it when not in use (d) put it in the bathroom
21. 21.🔋 Identical cells side by side (in parallel) give … (a) half the voltage (b) no voltage (c) double the voltage (d) the same voltage
22. 22.🌐 A soil sensor sends a reading to an app every 20 minutes. How many readings arrive in 3 hours?
23. 23.⚡ A device works on 5 V and takes 0.1 A. What is its power (in watts)? =
24. 24.💡 Why does an LED need a resistor in series? (a) to limit the current (b) to make it brighter (c) to store charge (d) to change its colour
25. 25.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) stay the same (c) smaller (d) bigger
26. 26.True or false: a dry cork is a conductor. (a) True (b) False
27. 27.True or false: to touch a fallen wire is not safe. (a) True (b) False
28. 28.📏 How many watts (W) is 0.5 kW?
29. 29.🔌 Is a steel spoon a conductor or an insulator? (a) an insulator (b) a conductor
30. 30.⚡ What does an exhaust fan mainly change electricity into? (a) movement (b) heat (c) sound (d) light
31. 31.🔁 What does “count = count + 1” do? (a) takes 1 away (b) sets count to 1 (c) prints 1 (d) adds 1 to count
32. 32.🧮 Resistors of 10 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?
33. 33.✏️ In a cell symbol, which line is the + terminal? (a) the shorter line (b) both lines (c) the longer line (d) neither line
34. 34.True or false: to install software updates is a good habit. (a) True (b) False
35. 35.🔁 What does a variable do in a program? (a) joins two wires (b) measures light (c) stores a value (d) blinks an LED
36. 36.🔗 Series or parallel circuit: “a single current path”? (a) series (b) parallel
37. 37.Which of these is safe? (a) poke things in a socket (b) stay away from pylons (c) touch a fallen wire (d) use a cable with cuts
38. 38.🌈 Which band is read first on a resistor? (a) the one nearest an end (b) the widest gap (c) any band (d) the gold band
39. 39.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
40. 40.📏 In the water-pipe picture of a circuit, current is like … (a) a narrow pipe (b) the pipe colour (c) the water pressure (d) the flow of water

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