Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 706 · 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.🔍 Which is the odd one out? (a) a buzzer (b) a ceiling fan (c) an electric toy car (d) an exhaust fan
2. 2.⚙️ Which actuator would you use to spin a robot’s wheels? (a) a pump (b) a buzzer (c) a motor (d) an LED
3. 3.Which of these is not safe? (a) stop if a part gets hot (b) fly kites in open fields (c) use mains for a project (d) build with an adult near
4. 4.🌐 How does a home IoT device usually send its data to the app? (a) through a candle (b) by shouting (c) by post (d) over Wi-Fi
5. 5.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 7 HIGH
   set pin 7 LOW
   set pin 7 LOW
   set pin 8 LOW
   Is the LED ON or OFF at the end? (a) ON (b) OFF
6. 6.🌐 Each reading a sensor sends is 25 bytes. How many bytes do 90 readings take?
7. 7.🧩 Which component has coloured bands? (a) thermistor (b) diode (c) LDR (d) resistor
8. 8.Which of these is an IoT device? (a) a wind-up clock (b) a paper calendar (c) a battery torch (d) a Wi-Fi weather station
9. 9.🔺 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
10. 10.Which drawing is the symbol for a resistor? (a) a circle with a cross (b) triangle, bar and arrows (c) a small empty box (d) a circle with M inside
11. 11.🔁 count = 4
    repeat 2 times { count = count + 6 }
    What is count at the end?
12. 12.🌐 Each reading a sensor sends is 25 bytes. How many bytes do 160 readings take?
13. 13.🔍 Which is the odd one out? (a) a graphite rod (b) a safety pin (c) aluminium foil (d) a ceramic cup
14. 14.⚡ A cell changes stored chemical energy into which kind of energy? (a) sound energy (b) wind energy (c) nuclear energy (d) electrical energy
15. 15.📶 Digital or analog: many values in a range? (a) digital (b) analog
16. 16.🔁 What does a variable do in a program? (a) joins two wires (b) stores a value (c) measures light (d) blinks an LED
17. 17.⏱️ repeat 9 times { buzzer ON; wait 400 ms; buzzer OFF; wait 1000 ms }
    How many milliseconds does this take in all?
18. 18.True or false: to leave the TV on standby saves electricity. (a) True (b) False
19. 19.Which of these is true of a parallel circuit? (a) many paths for current (b) bulbs share the voltage (c) a single current path (d) a break stops every bulb
20. 20.⚠️ Is it safe to keep drinks far away? (a) not safe (b) safe
21. 21.🔺 A 9 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
22. 22.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
23. 23.⚡ Power tells us … (a) the colour of light (b) the length of a wire (c) energy used each second (d) the size of a cell
24. 24.True or false: “an LED lights up” is the process. (a) True (b) False
25. 25.True or false: a laptop runs one small program. (a) True (b) False
26. 26.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a safety pin. Does the bulb glow? (a) Yes (b) No
27. 27.💡 5 identical bulbs are joined in parallel across a 12 V battery (ideal wires). How many volts does each bulb get? =
28. 28.🔘 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 OFF, C is OFF and D is OFF. Does the bulb glow? (a) No (b) Yes
29. 29.🌈 A resistor has the colour bands white, grey, orange. What is its value (in ohms)?
30. 30.🗺️ In an input → process → output plan, is “decide if soil is dry” the input, the process or the output? (a) output (b) input (c) process
31. 31.True or false: a motor makes things spin. (a) True (b) False
32. 32.🤖 if (temperature > 25) { fan ON } else { fan OFF }
    The temperature sensor reads 31 °C. What happens? (a) fan ON (b) fan OFF
33. 33.True or false: “each gets the full volts” is true of a parallel circuit. (a) False (b) True
34. 34.What does an LED do? (a) boosts a small signal (b) glows using little power (c) smooths a wobbly supply (d) senses how hot it is
35. 35.🔺 A current of 20 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
36. 36.⚠️ Which power source should children use for electronics projects? (a) an inverter socket (b) a small battery pack (c) a mains extension board (d) a wall socket
37. 37.💡 3 identical bulbs are joined in parallel across a 9 V battery (ideal wires). How many volts does each bulb get? =
38. 38.📏 How many kilo-ohms (kΩ) is 1400 Ω? =
39. 39.True or false: a plain rectangle is the symbol for an LED. (a) True (b) False
40. 40.What does an LDR do? (a) boosts a small signal (b) is a resistance knob (c) senses how bright it is (d) glows using little power

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