Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 182 · 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.🌐 In an IoT system, which part stores data online? (a) cloud server (b) Wi-Fi (c) phone app (d) actuator
2. 2.🔘 What does a switch do in a circuit? (a) opens or closes the loop (b) changes the voltage (c) makes electricity (d) stores current
3. 3.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
4. 4.💡 4 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulbs 3 and 4 are taken out of their holders. How many bulbs glow?
5. 5.🔋 3 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
6. 6.⚙️ Which actuator would you use to show a status light? (a) a servo motor (b) a motor (c) an LED (d) a buzzer
7. 7.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 230 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
8. 8.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 150 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
9. 9.🧮 Resistors of 68 Ω, 47 Ω, 330 Ω and 22 Ω are joined in series. What is the total resistance (in ohms)?
10. 10.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
11. 11.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) not joined (c) in parallel (d) by Wi-Fi
12. 12.🔁 What does “count = count + 1” do? (a) prints 1 (b) adds 1 to count (c) sets count to 1 (d) takes 1 away
13. 13.True or false: to cover unused cameras is a risky habit. (a) False (b) True
14. 14.🔺 A 6 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
15. 15.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) cell (b) junction (c) voltmeter (d) resistor
16. 16.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
17. 17.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 60 (c) 1000 (d) 100
18. 18.🔍 Which is the odd one out? (a) a light sensor (b) a push button (c) a small display (d) a motion sensor
19. 19.📏 How many amperes (A) is 2850 mA? =
20. 20.🔋 How many volts does one ordinary torch cell give? (a) 1.5 V (b) 230 V (c) 0.5 V (d) 15 V
21. 21.🧮 Five equal 25 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
22. 22.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a dry cork. Does the bulb glow? (a) No (b) Yes
23. 23.🔁 total = 0
    for i = 1 to 5 { total = total + i }
    What is total at the end?
24. 24.🔍 Which sensor would you use to stop a robot near walls? (a) a distance sensor (b) a sound sensor (c) a soil moisture sensor (d) a rain sensor
25. 25.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) the switch is OFF
26. 26.🔘 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) No (b) Yes
27. 27.🔌 Is a brass key a conductor or an insulator? (a) a conductor (b) an insulator
28. 28.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a glass marble. Does the bulb glow? (a) No (b) Yes
29. 29.🧮 Five equal 125 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
30. 30.True or false: “many paths for current” is true of a series circuit. (a) False (b) True
31. 31.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) gets bigger (c) becomes zero (d) gets smaller
32. 32.🔍 Which is the odd one out? (a) a buzzer beeps (b) an alert on the phone (c) the pump turns on (d) count button presses
33. 33.⚠️ Is it safe to build with an adult near? (a) not safe (b) safe
34. 34.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) − (negative) (b) + (positive)
35. 35.🔋 4 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
36. 36.⚡ A device works on 12 V and takes 2 A. What is its power (in watts)? =
37. 37.True or false: one tall, one short bar is the symbol for a cell. (a) False (b) True
38. 38.🌈 A resistor has the colour bands red, blue, red. What is its value (in ohms)?
39. 39.🌈 A resistor has the colour bands brown, brown, red. What is its value (in ohms)?
40. 40.📏 How many kilo-ohms (kΩ) is 6900 Ω? =

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