Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 964 · 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.💡 4 identical bulbs are in parallel and each one takes 0.5 A. What total current (in amperes) comes from the battery? =
2. 2.🔁 What does “count = count + 1” do? (a) prints 1 (b) takes 1 away (c) adds 1 to count (d) sets count to 1
3. 3.Which of these is safe? (a) poke things in a socket (b) touch a switch when wet (c) use small battery cells (d) fly a kite near wires
4. 4.🌈 A resistor has the colour bands violet, red, black. What is its value (in ohms)?
5. 5.Which of these is safe? (a) use a cable with cuts (b) use mains for a project (c) touch a fallen wire (d) stay away from pylons
6. 6.🔌 Why are electric wires covered in plastic? (a) plastic is a conductor (b) plastic makes current (c) plastic is an insulator (d) to make them heavy
7. 7.🔋 A 9 V battery and two 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
8. 8.🔍 Which is the odd one out? (a) a soil moisture reading (b) a motion sensor signal (c) a light level reading (d) an alert on the phone
9. 9.🌈 A resistor has the colour bands blue, red, red. What is its value in kilo-ohms (kΩ)? =
10. 10.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) − (negative) (b) + (positive)
11. 11.🤖 “if (A AND B)” is true when … (a) only A is true (b) both A and B are true (c) only B is true (d) both are false
12. 12.💡 What happens if an LED is put in backwards? (a) it does not light (b) it changes colour (c) it makes a sound (d) it lights brighter
13. 13.⚡ What does an LED lamp mainly change electricity into? (a) light (b) sound (c) heat (d) movement
14. 14.Which of these is measured in watts (W)? (a) how much a part resists (b) voltage (c) current (d) energy used each second
15. 15.Which of these is an insulator? (a) a steel spoon (b) a graphite rod (c) a copper wire (d) a dry cork
16. 16.True or false: a brass key is a conductor. (a) True (b) False
17. 17.📏 Voltmeter or ammeter: which one measures voltage? (a) ammeter (b) voltmeter
18. 18.🔘 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 OFF and C is ON. Does the bulb glow? (a) No (b) Yes
19. 19.🧮 Resistors of 150 Ω and 220 Ω are joined in series. What is the total resistance (in ohms)?
20. 20.🔋 How many 2 V cells must be joined in series to give 6 V?
21. 21.⚠️ Is it safe to stay away from pylons? (a) safe (b) not safe
22. 22.💡 A blue LED uses 3 V and should get 10 mA. It runs from a 9 V supply. What resistor (in ohms) is needed in series?
23. 23.🤖 if (temperature > 32) { fan ON } else { fan OFF }
    The temperature sensor reads 30 °C. What happens? (a) fan ON (b) fan OFF
24. 24.🔋 Does a generator give electricity or use electricity? (a) uses electricity (b) gives electricity
25. 25.⚡ What does a water heater mainly change electricity into? (a) heat (b) light (c) sound (d) movement
26. 26.Which of these is a risky habit? (a) cover unused cameras (b) turn off unused gadgets (c) read app permissions (d) accept every permission
27. 27.🔌 Is a glass marble a conductor or an insulator? (a) a conductor (b) an insulator
28. 28.🔍 Which is the odd one out? (a) a safety pin (b) a steel spoon (c) a wooden stick (d) a graphite rod
29. 29.True or false: “HIGH or LOW only” is an analog signal. (a) False (b) True
30. 30.🔋 A 9 V battery and four 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
31. 31.⚡ Power tells us … (a) the colour of light (b) energy used each second (c) the length of a wire (d) the size of a cell
32. 32.🔍 A distance sensor sends a sound pulse and hears the echo 17 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
33. 33.🔺 A current of 10 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
34. 34.🌈 A resistor has the colour bands blue, grey, red. What is its value in kilo-ohms (kΩ)? =
35. 35.📏 How many kilo-ohms (kΩ) is 1400 Ω? =
36. 36.⚡ A device works on 3 V and takes 0.2 A. What is its power (in watts)? =
37. 37.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the process (b) the input (c) the battery (d) the output
38. 38.⚡ A device works on 5 V and takes 0.5 A. What is its power (in watts)? =
39. 39.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
40. 40.What does the actuator do? (a) carries the data (b) measures the real world (c) acts on a command (d) reads values, decides

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