Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 549 · 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 of these is the input? (a) the pump turns on (b) a light level reading (c) an alert on the phone (d) the fan starts
2. 2.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) by Wi-Fi (c) not joined (d) in parallel
3. 3.True or false: a washing machine has no microcontroller inside. (a) False (b) True
4. 4.Which of these wastes electricity? (a) switch off empty rooms (b) close the fridge quickly (c) leave the TV on standby (d) use daylight to read
5. 5.🔍 Which is the odd one out? (a) a room heater (b) a school bell (c) an electric iron (d) an electric kettle
6. 6.Which drawing is the symbol for a voltmeter? (a) a straight line (b) a circle with V inside (c) many long-short pairs (d) a circle with A inside
7. 7.⚡ A device works on 1.5 V and takes 0.5 A. What is its power (in watts)? =
8. 8.True or false: to stop if a part gets hot is safe. (a) True (b) False
9. 9.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
10. 10.🔍 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)?
11. 11.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
12. 12.🌐 Is a smart energy meter an IoT device? (a) not an IoT device (b) an IoT device
13. 13.💡 A battery lights 4 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
14. 14.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) stays the same (c) gets bigger (d) gets smaller
15. 15.Which drawing is the symbol for a motor? (a) triangle against a bar (b) two or more cell symbols (c) a straight line (d) a circle with M inside
16. 16.True or false: on an LED, the shorter leg is the anode (+). (a) True (b) False
17. 17.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is ON and B is ON. Does the bulb glow? (a) Yes (b) No
18. 18.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
19. 19.🧩 Which component senses how hot it is? (a) thermistor (b) motor (c) LDR (d) buzzer
20. 20.⚠️ Is it safe to throw cells in a fire? (a) not safe (b) safe
21. 21.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
22. 22.🔍 For a microcontroller, is a sensor an input or an output? (a) a fuse (b) an input (c) an output (d) a power source
23. 23.🔺 A 30 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
24. 24.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
25. 25.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they explode (c) they get dimmer (d) they keep glowing
26. 26.True or false: “one out, the rest glow” is true of a series circuit. (a) True (b) False
27. 27.⚙️ What is an actuator? (a) an output that acts (b) a program (c) a battery (d) a sensor
28. 28.True or false: to start a fan when hot, use a temperature sensor. (a) False (b) True
29. 29.✏️ Why do engineers draw circuits with symbols? (a) symbols are heavier (b) to make it colourful (c) to hide the circuit (d) quick and clear for all
30. 30.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is ON, B is ON, C is OFF and D is OFF. Does the bulb glow? (a) No (b) Yes
31. 31.What does the microcontroller do? (a) shows data to you (b) stores data online (c) measures the real world (d) reads values, decides
32. 32.🔦 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 dry cork. Does the bulb glow? (a) No (b) Yes
33. 33.🔺 A 6 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
34. 34.⚠️ Is it safe to climb an electric pole? (a) not safe (b) safe
35. 35.True or false: a plain rectangle is the symbol for a resistor. (a) False (b) True
36. 36.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
37. 37.🗺️ Before building a project, what should you write down first? (a) the final price (b) inputs and outputs (c) the box colour (d) nothing at all
38. 38.🔺 A current of 2 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
39. 39.🔋 Does a computer give electricity or use electricity? (a) uses electricity (b) gives electricity
40. 40.Which of these is a risky habit? (a) change default passwords (b) set up with a parent (c) install software updates (d) tap unknown app links

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