Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 667 · 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.🔋 2 identical 1.2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
2. 2.True or false: to set the AC to 24 °C saves electricity. (a) False (b) True
3. 3.🔺 A current of 0.1 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
4. 4.🔺 A 6 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
5. 5.⚡ Power tells us … (a) energy used each second (b) the size of a cell (c) the colour of light (d) the length of a wire
6. 6.True or false: the ammeter is joined in series. (a) True (b) False
7. 7.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a plastic straw across the gap. Does the bulb glow? (a) No (b) Yes
8. 8.⚙️ Which actuator would you use to move water to plants? (a) a pump (b) a motor (c) an LED (d) a buzzer
9. 9.Which of these is true of a series circuit? (a) own switch for each bulb (b) one out, the rest glow (c) many paths for current (d) a break stops every bulb
10. 10.Which of these is not safe? (a) keep drinks far away (b) take cells out after use (c) fly a kite near wires (d) use small battery cells
11. 11.Which drawing is the symbol for an LED? (a) a circle with A inside (b) triangle, bar and arrows (c) many long-short pairs (d) two or more cell symbols
12. 12.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
13. 13.Which job needs a temperature sensor? (a) water a dry plant (b) measure classroom noise (c) switch on lamps at dusk (d) keep an incubator warm
14. 14.True or false: to keep drinks far away is safe. (a) False (b) True
15. 15.Which drawing is the symbol for a bulb? (a) many long-short pairs (b) a circle with A inside (c) a plain rectangle (d) a circle with an X in it
16. 16.True or false: to switch on with a clap, use a sound sensor. (a) True (b) False
17. 17.📏 Which unit measures how much a part resists? (a) ampere (A) (b) watt (W) (c) ohm (Ω) (d) volt (V)
18. 18.🔘 A cell and a bulb are joined to 3 side-by-side paths with one switch on each path — A, B and C (parallel). A is ON, B is ON and C is ON. Does the bulb glow? (a) Yes (b) No
19. 19.💡 5 identical bulbs are joined in series with a 7.5 V battery (ideal wires). How many volts does each bulb get? =
20. 20.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
21. 21.🔺 A current of 0.1 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
22. 22.Which of these is not safe? (a) take cells out after use (b) fly kites in open fields (c) poke things in a socket (d) stay away from pylons
23. 23.🧮 Two resistors in parallel give a total that is … (a) their sum (b) less than either one (c) more than either one (d) always zero
24. 24.🔘 Which kind of switch flips up or down? (a) a push button (b) a slide switch (c) a tilt switch (d) a toggle switch
25. 25.🔐 Why install updates on IoT devices? (a) they fix security holes (b) they make it heavier (c) they delete the Wi-Fi (d) they change the colour
26. 26.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) dimmer (c) the same
27. 27.True or false: to open a phone charger is not safe. (a) False (b) True
28. 28.🧮 A 33 Ω resistor is joined in series with two equal 330 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
29. 29.Which of these is true of a series circuit? (a) own switch for each bulb (b) one out, the rest glow (c) one bulb out, all go out (d) used in house wiring
30. 30.⚡ A 2.5 W device works on 5 V. What current does it take (in amperes)? =
31. 31.🔍 For a microcontroller, is a sensor an input or an output? (a) a fuse (b) an input (c) a power source (d) an output
32. 32.True or false: to open a phone charger is safe. (a) True (b) False
33. 33.⏱️ loop forever { LED ON; wait 1000 ms; LED OFF; wait 250 ms }
    How many milliseconds does one blink (ON + OFF) take?
34. 34.🔌 Why are electric wires covered in plastic? (a) plastic is a conductor (b) to make them heavy (c) plastic makes current (d) plastic is an insulator
35. 35.True or false: “used in house wiring” is true of a series circuit. (a) False (b) True
36. 36.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) zero (c) stay the same (d) bigger
37. 37.⚠️ Is it safe to use mains for a project? (a) safe (b) not safe
38. 38.🔁 count = 4
    while (count < 12) { count = count + 2 }
    How many times does the loop run?
39. 39.🔁 x = 2
    repeat 2 times { x = x × 2 }
    What is x at the end?
40. 40.🔺 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

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