Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 861 · 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 cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a parallel circuit (b) a short circuit (c) a safe circuit (d) an open circuit
2. 2.🧩 Which component makes a beeping sound? (a) LDR (b) resistor (c) diode (d) buzzer
3. 3.⚡ Power tells us … (a) the length of a wire (b) the colour of light (c) energy used each second (d) the size of a cell
4. 4.🌈 A resistor has the colour bands orange, blue, black. What is its value (in ohms)?
5. 5.📏 How many amperes (A) is 2680 mA? =
6. 6.True or false: the ammeter is joined in series. (a) False (b) True
7. 7.🔁 repeat 6 times { repeat 5 times { beep } }
   How many beeps are there?
8. 8.📶 Digital or analog: the room temperature? (a) digital (b) analog
9. 9.🔋 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
10. 10.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
11. 11.🔘 A cell, a bulb and switches A, B, C and D are joined one after another in a single loop (series). A is ON, B is ON, C is ON and D is ON. Does the bulb glow? (a) No (b) Yes
12. 12.🤖 if (distance < 15) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 10 cm. What happens? (a) buzzer is silent (b) buzzer beeps
13. 13.⚡ A fan changes electrical energy mainly into which kind of energy? (a) chemical energy (b) light energy (c) movement energy (d) sound energy
14. 14.🤖 if (light < 300) { lamp ON } else { lamp OFF }
    The light sensor reads 194. What happens? (a) lamp ON (b) lamp OFF
15. 15.💡 2 identical bulbs are in parallel and each one takes 1.5 A. What total current (in amperes) comes from the battery? =
16. 16.Which of these is true of a parallel circuit? (a) a single current path (b) one out, the rest glow (c) a break stops every bulb (d) bulbs share the voltage
17. 17.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 watt (c) 1 ampere (d) 1 volt
18. 18.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) the bulb is unscrewed
19. 19.🔍 Which is the odd one out? (a) a doorbell (b) a siren (c) a ceiling fan (d) a loudspeaker
20. 20.🔋 Cells joined + to − in a row (series) give … (a) the same voltage (b) a smaller voltage (c) a bigger voltage (d) no voltage
21. 21.🔋 3 identical 3 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
22. 22.🤖 Does a digital alarm clock usually have a microcontroller inside? (a) Yes (b) No
23. 23.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) straight lines (c) dotted circles (d) little stars
24. 24.🔁 count = 3
    repeat 10 times { count = count + 6 }
    What is count at the end?
25. 25.🔍 Which is the odd one out? (a) leave the TV on standby (b) leave fridge door open (c) run fans in empty rooms (d) set the AC to 24 °C
26. 26.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a steel spoon across the gap. Does the bulb glow? (a) No (b) Yes
27. 27.🧮 A 5.5 V battery is joined to 3 Ω and 8 Ω resistors in series. What current flows (in amperes)? =
28. 28.💡 2 identical bulbs are joined in parallel across a 3 V battery (ideal wires). How many volts does each bulb get? =
29. 29.🤖 if (temperature > 37) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
    The temperature is 42 °C. What is shown? (a) Warm (b) Hot (c) Cool
30. 30.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 40000 Ω resistor? (a) yellow-black-orange (b) yellow-black-red (c) yellow-black-yellow (d) green-yellow-orange
31. 31.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
32. 32.True or false: a school bell mainly makes sound. (a) True (b) False
33. 33.🧩 Which component senses how hot it is? (a) LDR (b) resistor (c) motor (d) thermistor
34. 34.⏱️ repeat 7 times { buzzer ON; wait 500 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
35. 35.🔁 count = 9
    repeat 2 times { count = count + 10 }
    What is count at the end?
36. 36.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 1024 (b) 10 (c) 100 (d) 1000
37. 37.True or false: on an LED, the shorter leg is the cathode (−). (a) False (b) True
38. 38.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is ON, B is OFF and C is ON. Does the bulb glow? (a) Yes (b) No
39. 39.⚠️ Why must we never touch switches with wet hands? (a) it is just untidy (b) water makes it cold (c) it spoils the paint (d) water carries current
40. 40.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire is cut (c) a cell is taken out (d) all wires are joined

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