Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 643 · 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.📶 Digital or analog: a knob turned part way? (a) analog (b) digital
2. 2.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
3. 3.True or false: a circle with V inside is the symbol for a voltmeter. (a) False (b) True
4. 4.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the input (b) the battery (c) the output (d) the process
5. 5.⏱️ repeat 3 times { buzzer ON; wait 100 ms; buzzer OFF; wait 400 ms }
   How many milliseconds does this take in all?
6. 6.Which of these is the output? (a) a motion sensor signal (b) a soil moisture reading (c) the pump turns on (d) count button presses
7. 7.🔁 x = 5
   repeat 3 times { x = x × 2 }
   What is x at the end?
8. 8.🔦 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) No (b) Yes
9. 9.💡 5 identical bulbs are joined in series with a 7.5 V battery (ideal wires). How many volts does each bulb get? =
10. 10.🔋 Does a generator give electricity or use electricity? (a) gives electricity (b) uses electricity
11. 11.🔺 A current of 20 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
12. 12.True or false: to stop a robot near walls, use a distance sensor. (a) True (b) False
13. 13.🔢 To plan an electronics project, what comes right after “list inputs and outputs”? (a) pick a problem to solve (b) build it with an adult (c) test it and fix it (d) draw the circuit diagram
14. 14.🌈 In the resistor colour code, which number does red stand for?
15. 15.🔺 A 10 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
16. 16.🧩 Which component has coloured bands? (a) diode (b) resistor (c) motor (d) LED
17. 17.Which of these is not safe? (a) fly kites in open fields (b) build with an adult near (c) touch a switch when wet (d) dry your hands first
18. 18.True or false: to keep factory passwords is a risky habit. (a) True (b) False
19. 19.True or false: a rubber eraser is a conductor. (a) True (b) False
20. 20.🌈 A resistor has the colour bands grey, black, black. What is its value (in ohms)?
21. 21.Which of these gives us electricity? (a) a water pump (b) a cell (c) a refrigerator (d) a computer
22. 22.📏 How many watts (W) is 1.4 kW?
23. 23.Which job needs a pump? (a) spin a robot’s wheels (b) show a status light (c) show the temperature (d) move water to plants
24. 24.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) to save copper only (c) so all go off together (d) to make bulbs dim
25. 25.🔘 What does a switch do in a circuit? (a) changes the voltage (b) stores current (c) makes electricity (d) opens or closes the loop
26. 26.🔘 Two switches are in series. When does the bulb glow? (a) when both are ON (b) when either is ON (c) when both are OFF (d) never
27. 27.🔺 A 0.5 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
28. 28.True or false: “each gets the full volts” is true of a series circuit. (a) True (b) False
29. 29.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
30. 30.💡 An LED is joined to a 5 V battery through a 220 Ω resistor; its long leg goes to the − side and its short leg to the + side. What happens? (a) does not light (b) lights up (c) may burn out
31. 31.Which drawing is the symbol for a voltmeter? (a) a small empty box (b) two equal parallel lines (c) a line lifted at a gap (d) a circle with V inside
32. 32.⏱️ A program says “wait 7250 ms”. How many seconds is that? =
33. 33.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) by Wi-Fi (c) in series (d) not joined
34. 34.🔋 A 6 V battery and four 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
35. 35.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 0 % (c) 25 % (d) 5 %
36. 36.🔍 Which is the odd one out? (a) a Wi-Fi doorbell camera (b) a smart energy meter (c) a battery torch (d) a Wi-Fi weather station
37. 37.💡 4 identical bulbs are in parallel and each one takes 0.25 A. What total current (in amperes) comes from the battery? =
38. 38.⏱️ A program says “wait 7000 ms”. How many seconds is that? =
39. 39.What does a toggle switch do? (a) slides side to side (b) closes when tipped over (c) flips up or down (d) works only while pressed
40. 40.💡 6 identical bulbs are in parallel and each bulb has its own switch on its path. 4 of the switches are OFF and the rest are ON. How many bulbs glow?

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