Electronics Worksheet: Components and Ohm’s Law Test

Electronics lesson 20: Part 2 test: components and Ohm’s law · Set 81 · 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.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 kilowatt-hour (kWh) (c) 1 volt (d) 1 watt
2. 2.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 600 Ω resistor? (a) blue-black-black (b) blue-black-red (c) blue-black-brown (d) violet-blue-brown
3. 3.💡 What does LED stand for? (a) light-emitting diode (b) light energy dial (c) large electric dial (d) low energy device
4. 4.🧩 Which component limits the current? (a) potentiometer (b) buzzer (c) capacitor (d) resistor
5. 5.True or false: the voltmeter is joined in series. (a) True (b) False
6. 6.📏 How many kilo-ohms (kΩ) is 8700 Ω? =
7. 7.🔺 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
8. 8.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
9. 9.🔺 A 2.5 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
10. 10.🔍 Which is the odd one out? (a) use daylight to read (b) use old filament bulbs (c) use LED lamps (d) close the fridge quickly
11. 11.🔺 A 1.2 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
12. 12.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 0 % (c) 5 % (d) 25 %
13. 13.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
14. 14.📏 Which unit measures current? (a) watt (W) (b) volt (V) (c) ampere (A) (d) ohm (Ω)
15. 15.🧩 Which component turns a fan or wheels? (a) diode (b) motor (c) potentiometer (d) LDR
16. 16.🔺 A 1.5 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
17. 17.🔺 A current of 10 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
18. 18.📏 How many kilowatts (kW) is 3400 W? =
19. 19.True or false: power is measured in watts (W). (a) True (b) False
20. 20.🧮 Resistors of 33 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
21. 21.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets smaller (b) becomes zero (c) stays the same (d) gets bigger
22. 22.🔺 A 23.5 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
23. 23.🌈 A resistor has the colour bands red, violet, yellow. What is its value in kilo-ohms (kΩ)? =
24. 24.Which of these is measured in amperes (A)? (a) how much a part resists (b) energy used each second (c) current (d) the push of a cell
25. 25.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 59 Ω resistor? (a) green-white-brown (b) white-green-black (c) blue-white-black (d) green-white-black
26. 26.🌈 A resistor has the colour bands yellow, yellow, black. What is its value (in ohms)?
27. 27.⚡ A 6 W device works on 12 V. What current does it take (in amperes)? =
28. 28.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 2200 Ω resistor? (a) red-red-orange (b) red-red-brown (c) red-red-red (d) red-orange-red
29. 29.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
30. 30.🧮 A 220 Ω resistor is joined in series with two equal 220 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
31. 31.🔺 A 3 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
32. 32.📏 How many kilo-ohms (kΩ) is 3400 Ω? =
33. 33.⚡ A 1.2 W device works on 6 V. What current does it take (in amperes)? =
34. 34.🔺 A current of 25 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
35. 35.🔺 A current of 50 mA flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
36. 36.📏 How many milliamperes (mA) is 0.7 A?
37. 37.📏 Voltmeter or ammeter: which one measures current? (a) voltmeter (b) ammeter
38. 38.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a capacitor (c) a diode (d) a resistor
39. 39.📏 How many watts (W) is 0.1 kW?
40. 40.🧮 Resistors of 20 Ω, 33 Ω, 220 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?

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