Electronics Worksheet: Components and Ohm’s Law Test

Electronics lesson 20: Part 2 test: components and Ohm’s law · Set 1 · 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.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V + I (c) R = I ÷ V (d) R = V × I
2. 2.Which of these wastes electricity? (a) use daylight to read (b) close the fridge quickly (c) use LED lamps (d) use old filament bulbs
3. 3.🧮 A 22 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)?
4. 4.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 7800 Ω resistor? (a) violet-grey-brown (b) grey-violet-red (c) violet-grey-red (d) violet-grey-orange
5. 5.🔺 A current of 1 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
6. 6.📏 How many milliamperes (mA) is 0.58 A?
7. 7.🧮 Resistors of 22 Ω, 47 Ω and 22 Ω are joined in series. What is the total resistance (in ohms)?
8. 8.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) stay the same (c) bigger (d) zero
9. 9.📏 How many kilowatts (kW) is 2400 W? =
10. 10.⚡ A 3 W device works on 3 V. What current does it take (in amperes)? =
11. 11.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 5800 Ω resistor? (a) green-grey-brown (b) green-grey-red (c) grey-green-red (d) green-grey-orange
12. 12.🔺 A current of 0.5 A flows when 1.5 V is joined across a resistor. What is its resistance (in ohms)?
13. 13.🧮 A 47 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)?
14. 14.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V + R (c) I = R ÷ V (d) I = V × R
15. 15.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
16. 16.🔺 A current of 20 mA flows when 8 V is joined across a resistor. What is its resistance (in ohms)?
17. 17.🔺 A current of 0.25 A flows when 1.5 V is joined across a resistor. What is its resistance (in ohms)?
18. 18.Which of these is measured in ohms (Ω)? (a) resistance (b) current (c) the flow of charge (d) power
19. 19.🔺 A current of 1.5 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
20. 20.Which of these is measured in watts (W)? (a) the push of a cell (b) current (c) the flow of charge (d) energy used each second
21. 21.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
22. 22.🔺 A current of 0.25 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
23. 23.True or false: a transistor stores a little charge. (a) False (b) True
24. 24.🔺 A current of 20 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
25. 25.True or false: a capacitor smooths a wobbly supply. (a) False (b) True
26. 26.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 41 Ω resistor? (a) yellow-brown-black (b) brown-yellow-black (c) green-brown-black (d) yellow-brown-brown
27. 27.🧮 Three equal 60 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
28. 28.📏 How many amperes (A) is 1490 mA? =
29. 29.🔺 A current of 1 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
30. 30.What does a resistor do? (a) stores a little charge (b) glows using little power (c) has coloured bands (d) boosts a small signal
31. 31.Which of these is measured in watts (W)? (a) the push of a cell (b) resistance (c) current (d) power
32. 32.🔺 A current of 20 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
33. 33.🌈 A resistor has the colour bands orange, violet, orange. What is its value (in ohms)?
34. 34.🔺 A current of 2 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
35. 35.📏 How many kilowatts (kW) is 4650 W? =
36. 36.⚡ A device works on 1.5 V and takes 0.2 A. What is its power (in watts)? =
37. 37.🧩 Which component senses how hot it is? (a) buzzer (b) thermistor (c) resistor (d) transistor
38. 38.🧮 Two equal 1000 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
39. 39.🔺 A 22.5 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
40. 40.🧮 A 33 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)?

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