Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 59 · 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 a series circuit, how many paths does the current have? (a) none (b) two (c) one (d) one for each bulb
2. 2.🌐 Each reading a sensor sends is 20 bytes. How many bytes do 30 readings take?
3. 3.Which of these is an insulator? (a) a ceramic cup (b) a brass key (c) a copper wire (d) an iron nail
4. 4.📏 Which unit measures energy used each second? (a) volt (V) (b) ohm (Ω) (c) ampere (A) (d) watt (W)
5. 5.⚡ A 4.5 W device works on 1.5 V. What current does it take (in amperes)? =
6. 6.Which of these is safe? (a) build with an adult near (b) poke things in a socket (c) use mains for a project (d) touch a fallen wire
7. 7.Which of these is the input? (a) the pump turns on (b) a motion sensor signal (c) a buzzer beeps (d) decide if soil is dry
8. 8.⚡ What does an exhaust fan mainly change electricity into? (a) light (b) heat (c) sound (d) movement
9. 9.Which of these is safe? (a) use mains for a project (b) throw cells in a fire (c) stay away from pylons (d) open a phone charger
10. 10.🤖 if (distance < 30) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 29 cm. What happens? (a) buzzer beeps (b) buzzer is silent
11. 11.True or false: a resistor has coloured bands. (a) False (b) True
12. 12.🔺 A 16.5 V supply is joined across a 330 Ω resistor. What current flows (in milliamperes, mA)?
13. 13.🔺 A 0.8 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
14. 14.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = V + I (c) R = V ÷ I (d) R = I ÷ V
15. 15.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they get dimmer (b) they all go out (c) they keep glowing (d) they explode
16. 16.🔁 count = 5
    while (count < 21) { count = count + 4 }
    How many times does the loop run?
17. 17.🔋 2 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
18. 18.Which of these is not safe? (a) open a phone charger (b) take cells out after use (c) use small battery cells (d) fly kites in open fields
19. 19.True or false: a loudspeaker mainly makes sound. (a) True (b) False
20. 20.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 8 LOW
    set pin 8 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
21. 21.🔘 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 OFF, B is ON and C is ON. Does the bulb glow? (a) No (b) Yes
22. 22.📶 A pin set LOW gives about … (a) 9 V (b) 5 V (c) 1.5 V (d) 0 V
23. 23.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) True (b) False
24. 24.🔺 A current of 1 A flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
25. 25.📏 Which unit measures the push of a cell? (a) ohm (Ω) (b) ampere (A) (c) volt (V) (d) watt (W)
26. 26.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) True (b) False
27. 27.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 3 is taken out of its holder. Does bulb 4 glow? (a) No (b) Yes
28. 28.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) none (d) both of them
29. 29.True or false: to keep factory passwords is a risky habit. (a) False (b) True
30. 30.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put aluminium foil across the gap. Does the bulb glow? (a) Yes (b) No
31. 31.Which of these is a good habit? (a) share only needed data (b) share the Wi-Fi key (c) reuse one password (d) share camera links
32. 32.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a short circuit (b) a parallel circuit (c) an open circuit (d) a safe circuit
33. 33.⚙️ Which actuator would you use to move water to plants? (a) a motor (b) a display (c) a pump (d) a servo motor
34. 34.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I + R (c) V = I × R (d) V = I ÷ R
35. 35.Which drawing is the symbol for a capacitor? (a) two equal parallel lines (b) a straight line (c) one tall, one short bar (d) a circle with A inside
36. 36.🔍 Which is the odd one out? (a) a plastic straw (b) a copper wire (c) a plastic ruler (d) a glass marble
37. 37.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 4 V supply. What current flows (in mA)?
38. 38.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
39. 39.🤖 if (light < 400) { lamp ON } else { lamp OFF }
    The light sensor reads 282. What happens? (a) lamp OFF (b) lamp ON
40. 40.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No

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