Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 423 · 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.🔋 8 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
2. 2.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. Does bulb 1 glow? (a) No (b) Yes
3. 3.🔌 Is a steel spoon a conductor or an insulator? (a) an insulator (b) a conductor
4. 4.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 70 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
5. 5.🔺 A current of 0.5 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
6. 6.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V + I (c) P = V × I (d) P = I ÷ V
7. 7.🧾 A 1500 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
8. 8.🧮 A 0.9 V battery is joined to 5 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
9. 9.🔁 repeat 2 times { repeat 6 times { beep } }
   How many beeps are there?
10. 10.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) a cell is taken out
11. 11.🔐 Is it a good or a risky habit to read app permissions? (a) good habit (b) risky habit
12. 12.🤖 “if (A AND B)” is true when … (a) both A and B are true (b) both are false (c) only A is true (d) only B is true
13. 13.⏱️ How many milliseconds is a wait of 0.8 seconds?
14. 14.⚡ A device works on 1.5 V and takes 1.5 A. What is its power (in watts)? =
15. 15.⏱️ repeat 2 times { buzzer ON; wait 1000 ms; buzzer OFF; wait 500 ms }
    How many milliseconds does this take in all?
16. 16.🌈 A resistor has the colour bands blue, brown, red. What is its value in kilo-ohms (kΩ)? =
17. 17.True or false: a microcontroller needs much more power. (a) False (b) True
18. 18.True or false: “one bulb out, all go out” is true of a series circuit. (a) False (b) True
19. 19.What does a slide switch do? (a) flips up or down (b) springs back when let go (c) closes near a magnet (d) slides side to side
20. 20.True or false: to switch on with a clap, use a gas sensor. (a) True (b) False
21. 21.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = I + R (c) V = I ÷ R (d) V = R ÷ I
22. 22.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a resistor (c) a diode (d) a capacitor
23. 23.Which of these is the output? (a) check if temp > 30 (b) a motion sensor signal (c) decide if soil is dry (d) the fan starts
24. 24.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a safety pin across the gap. Does the bulb glow? (a) No (b) Yes
25. 25.True or false: energy used each second is measured in amperes (A). (a) True (b) False
26. 26.⚡ A 0.3 W device works on 3 V. What current does it take (in amperes)? =
27. 27.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 ampere (c) 1 kilowatt-hour (kWh) (d) 1 watt
28. 28.🔋 How many volts does one ordinary torch cell give? (a) 230 V (b) 15 V (c) 0.5 V (d) 1.5 V
29. 29.🔍 Which is the odd one out? (a) use a cable with cuts (b) touch a switch when wet (c) touch a fallen wire (d) keep drinks far away
30. 30.🔁 repeat 6 times { repeat 6 times { beep } }
    How many beeps are there?
31. 31.⚡ Power tells us … (a) the colour of light (b) the size of a cell (c) energy used each second (d) the length of a wire
32. 32.💡 3 identical bulbs are in parallel and each one takes 1 A. What total current (in amperes) comes from the battery? =
33. 33.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
34. 34.🔺 A 3 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
35. 35.True or false: to close the fridge quickly saves electricity. (a) False (b) True
36. 36.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
37. 37.True or false: to poke things in a socket is safe. (a) True (b) False
38. 38.True or false: the ammeter measures voltage. (a) True (b) False
39. 39.🌈 A resistor has the colour bands red, violet, yellow. What is its value in kilo-ohms (kΩ)? =
40. 40.⚡ A device works on 3 V and takes 0.2 A. What is its power (in watts)? =

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