Electronics Worksheet: Components and Ohm’s Law Test

Electronics lesson 20: Part 2 test: components and Ohm’s law · Set 60 · 40 questions

Remember (Find the topic, use the formula): Find the topic and the formula: V = I × R, I = V ÷ R, R = V ÷ I, P = V × I, units = W × h ÷ 1000. Change mA to A and kΩ to Ω before using a formula. Check: put your answer back into the formula.

1. 1.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V × I (c) P = V + I (d) P = V ÷ I
2. 2.🧾 Which lamp gives the same light for the least power? (a) a candle (b) an LED lamp (c) an oil lamp (d) a filament bulb
3. 3.🧮 A 4 V battery is joined to 8 Ω and 8 Ω resistors in series. What current flows (in amperes)? =
4. 4.📏 Voltmeter or ammeter: which one is joined across a part? (a) ammeter (b) voltmeter
5. 5.🔍 Which is the odd one out? (a) switch off empty rooms (b) use LED lamps (c) close the fridge quickly (d) run fans in empty rooms
6. 6.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 0 % (c) 5 % (d) 25 %
7. 7.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 160 Ω resistor? (a) blue-brown-brown (b) brown-blue-red (c) brown-blue-black (d) brown-blue-brown
8. 8.🧾 A 1000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
9. 9.🔺 A current of 0.1 A flows when 0.5 V is joined across a resistor. What is its resistance (in ohms)?
10. 10.📏 Which unit measures power? (a) volt (V) (b) ampere (A) (c) watt (W) (d) ohm (Ω)
11. 11.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) becomes zero (c) gets smaller (d) stays the same
12. 12.True or false: a diode blows if current is high. (a) True (b) False
13. 13.True or false: on an LED, the leg by the flat edge is the anode (+). (a) False (b) True
14. 14.🧾 A family uses 180 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
15. 15.🔺 A current of 1 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
16. 16.🧮 A 50 Ω resistor is joined in series with two equal 330 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
17. 17.Which of these saves electricity? (a) switch off empty rooms (b) use old filament bulbs (c) iron one shirt at a time (d) leave the TV on standby
18. 18.True or false: how much a part resists is measured in ohms (Ω). (a) False (b) True
19. 19.🧮 Three equal 30 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
20. 20.⚡ A 6 W device works on 3 V. What current does it take (in amperes)? =
21. 21.Which of these saves electricity? (a) use old filament bulbs (b) leave the TV on standby (c) use LED lamps (d) leave fridge door open
22. 22.🧮 A 330 Ω resistor is joined in series with two equal 10 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
23. 23.Which of these is measured in amperes (A)? (a) power (b) voltage (c) how much a part resists (d) current
24. 24.🌈 Which band is read first on a resistor? (a) the widest gap (b) any band (c) the one nearest an end (d) the gold band
25. 25.🧮 Three equal 15 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
26. 26.📏 Which unit measures voltage? (a) ampere (A) (b) ohm (Ω) (c) volt (V) (d) watt (W)
27. 27.Which of these wastes electricity? (a) iron one shirt at a time (b) unplug idle chargers (c) close the fridge quickly (d) set the AC to 24 °C
28. 28.🔺 A current of 50 mA flows when 12.5 V is joined across a resistor. What is its resistance (in ohms)?
29. 29.🧩 Which component senses how bright it is? (a) thermistor (b) transistor (c) LDR (d) buzzer
30. 30.🔺 A current of 40 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
31. 31.🌈 A resistor has the colour bands violet, blue, brown. What is its value (in ohms)?
32. 32.🔺 A current of 10 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
33. 33.🔺 A 2.4 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
34. 34.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
35. 35.🔺 A current of 1.5 A flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
36. 36.🔺 A 4 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
37. 37.🧩 Which component beeps for an alarm? (a) resistor (b) buzzer (c) capacitor (d) motor
38. 38.⚡ A device works on 1.5 V and takes 1 A. What is its power (in watts)? =
39. 39.🔺 A current of 25 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
40. 40.🔺 A current of 25 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids