Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 874 · 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.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) type it all in (b) post it online (c) share it with friends (d) ask a parent first
2. 2.True or false: to fly kites in open fields is safe. (a) True (b) False
3. 3.⚠️ About how many volts do home sockets in India supply? (a) 9 V (b) 230 V (c) 12 V (d) 1.5 V
4. 4.True or false: the ammeter measures current. (a) False (b) True
5. 5.🔺 A current of 0.5 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
6. 6.🔍 Which is the odd one out? (a) use a cable with cuts (b) fly a kite near wires (c) stay away from pylons (d) touch a switch when wet
7. 7.Which of these is true of a parallel circuit? (a) a single current path (b) a break stops every bulb (c) bulbs share the voltage (d) many paths for current
8. 8.Which of these is an IoT device? (a) a plain table fan (b) a Wi-Fi weather station (c) a paper calendar (d) a plain wall switch
9. 9.💡 5 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. Bulb 3 is taken out of its holder. How many bulbs glow?
10. 10.💡 4 identical bulbs are joined in series with a 16 V battery (ideal wires). How many volts does each bulb get? =
11. 11.⚡ A device works on 9 V and takes 1 A. What is its power (in watts)? =
12. 12.Which of these is measured in watts (W)? (a) resistance (b) the push of a cell (c) voltage (d) power
13. 13.🌐 A weather station sends one reading every 20 seconds. How many readings does it send in 10 minutes?
14. 14.🔁 total = 0
    for i = 1 to 7 { total = total + i }
    What is total at the end?
15. 15.What does a reed switch do? (a) works only while pressed (b) flips up or down (c) closes near a magnet (d) springs back when let go
16. 16.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) wavy lines (c) dotted circles (d) straight lines
17. 17.🔺 A current of 10 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
18. 18.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
19. 19.🔐 Who should decide which smart devices go in a child’s room? (a) an online stranger (b) the app’s adverts (c) nobody at all (d) a parent or guardian
20. 20.True or false: many long-short pairs is the symbol for a battery. (a) True (b) False
21. 21.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V × R (c) I = V + R (d) I = V ÷ R
22. 22.🔌 Is a metal paper clip a conductor or an insulator? (a) an insulator (b) a conductor
23. 23.🔋 Cells joined + to − in a row (series) give … (a) no voltage (b) a bigger voltage (c) the same voltage (d) a smaller voltage
24. 24.🔺 A current of 2.5 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
25. 25.🔺 A current of 25 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
26. 26.Which of these is a risky habit? (a) reuse one password (b) cover unused cameras (c) log out of shared phones (d) set a strong password
27. 27.Which of these is the process? (a) a temperature reading (b) a motion sensor signal (c) an LED lights up (d) decide if soil is dry
28. 28.🧩 Which component limits the current? (a) resistor (b) motor (c) potentiometer (d) buzzer
29. 29.✏️ In a cell symbol, which line is the + terminal? (a) the shorter line (b) the longer line (c) both lines (d) neither line
30. 30.📏 How many kilowatts (kW) is 1600 W? =
31. 31.🔁 What does a variable do in a program? (a) measures light (b) stores a value (c) blinks an LED (d) joins two wires
32. 32.⏱️ loop forever { LED ON; wait 900 ms; LED OFF; wait 950 ms }
    How many milliseconds does one blink (ON + OFF) take?
33. 33.True or false: a resistor turns a fan or wheels. (a) True (b) False
34. 34.⚡ A device works on 24 V and takes 0.2 A. What is its power (in watts)? =
35. 35.🤖 if (moisture < 50) { pump ON } else { pump OFF }
    The soil moisture sensor reads 42 %. What happens? (a) pump ON (b) pump OFF
36. 36.True or false: one tall, one short bar is the symbol for a cell. (a) True (b) False
37. 37.🌈 In the resistor colour code, which number does grey stand for?
38. 38.🔋 Does a wind turbine give electricity or use electricity? (a) uses electricity (b) gives electricity
39. 39.🔍 A distance sensor sends a sound pulse and hears the echo 6 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
40. 40.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they get dimmer (c) they keep glowing (d) they explode

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