Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 715 · 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.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) True (b) False
2. 2.🔋 A 12 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
3. 3.⚠️ Someone is getting a shock and is still touching a wire. What should you do? (a) wait and watch (b) pour water on them (c) pull them by the hand (d) shout for an adult
4. 4.🧾 A 50 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
5. 5.🌈 In the resistor colour code, which number does brown stand for?
6. 6.📏 Which unit measures resistance? (a) ampere (A) (b) watt (W) (c) ohm (Ω) (d) volt (V)
7. 7.🔋 4 identical 1.5 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
8. 8.🔺 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
9. 9.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) many paths for current (c) bulbs share the voltage (d) one bulb out, all go out
10. 10.True or false: on an LED, the round-side leg is the cathode (−). (a) False (b) True
11. 11.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
12. 12.True or false: “the pump turns on” is the output. (a) False (b) True
13. 13.True or false: on an LED, the leg by the flat edge is the anode (+). (a) False (b) True
14. 14.🔁 x = 1
    repeat 2 times { x = x × 2 }
    What is x at the end?
15. 15.🔐 Is it a good or a risky habit to log out of shared phones? (a) risky habit (b) good habit
16. 16.🔋 3 identical 1.5 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
17. 17.🤖 Microcontroller or laptop: which one uses very little power? (a) microcontroller (b) laptop
18. 18.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
19. 19.Which of these is not safe? (a) dry your hands first (b) climb an electric pole (c) use small battery cells (d) fly kites in open fields
20. 20.⚙️ Which actuator would you use to move water to plants? (a) a display (b) a pump (c) a motor (d) an LED
21. 21.Which of these uses electricity? (a) a battery (b) a generator (c) a cell (d) a computer
22. 22.📏 How many milliamperes (mA) is 0.62 A?
23. 23.Which drawing is the symbol for a switch? (a) a line lifted at a gap (b) triangle, bar and arrows (c) a circle with a cross (d) one tall, one short bar
24. 24.True or false: on a cell, “the shorter symbol line” means the − (negative) end. (a) False (b) True
25. 25.💡 5 identical bulbs are joined in series with a 12.5 V battery (ideal wires). How many volts does each bulb get? =
26. 26.🤖 “if (A AND B)” is true when … (a) only B is true (b) both A and B are true (c) both are false (d) only A is true
27. 27.🌐 What does IoT stand for? (a) Inside of Toys (b) Internet of Talk (c) Internet of Things (d) Input of Tools
28. 28.🔍 Which is the odd one out? (a) compare with a limit (b) count button presses (c) a soil moisture reading (d) decide if soil is dry
29. 29.Which of these mainly gives out light? (a) a mixer grinder (b) a torch (c) an electric drill (d) a water heater
30. 30.True or false: “the fan starts” is the output. (a) False (b) True
31. 31.True or false: on an LED, the longer leg is the anode (+). (a) False (b) True
32. 32.Which of these mainly makes sound? (a) an electric toy car (b) a table fan (c) a school bell (d) an electric kettle
33. 33.🔘 Which kind of switch slides side to side? (a) a slide switch (b) a toggle switch (c) a push button (d) a reed switch
34. 34.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
35. 35.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) their sum (c) always zero (d) less than either one
36. 36.🔺 A current of 20 mA flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
37. 37.🔋 What should you do with used-up cells? (a) bury them in soil (b) throw them in a fire (c) cut them open (d) give them for recycling
38. 38.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
39. 39.True or false: a safety pin is a conductor. (a) False (b) True
40. 40.🧩 Which component stores a little charge? (a) capacitor (b) fuse (c) diode (d) LDR

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