Electronics Worksheet: Components and Ohm’s Law Test

Electronics lesson 20: Part 2 test: components and Ohm’s law · Set 428 · 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.🧮 A 100 Ω resistor is joined in series with two equal 50 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
2. 2.🧮 A 1.75 V battery is joined to 2 Ω and 5 Ω resistors in series. What current flows (in amperes)? =
3. 3.📏 Voltmeter or ammeter: which one is joined across a part? (a) ammeter (b) voltmeter
4. 4.True or false: to switch off empty rooms saves electricity. (a) False (b) True
5. 5.🔺 In the V-I-R triangle, how do we find V? (a) V = I + R (b) V = R ÷ I (c) V = I × R (d) V = I ÷ R
6. 6.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
7. 7.📏 How many watts (W) is 4.4 kW?
8. 8.🧮 Five equal 500 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
9. 9.🔍 Which is the odd one out? (a) unplug idle chargers (b) use old filament bulbs (c) switch off empty rooms (d) use daylight to read
10. 10.⚡ A device works on 3 V and takes 0.2 A. What is its power (in watts)? =
11. 11.True or false: a capacitor has coloured bands. (a) True (b) False
12. 12.True or false: on an LED, the round-side leg is the anode (+). (a) False (b) True
13. 13.🧮 A 330 Ω resistor is joined in series with two equal 50 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
14. 14.Which of these wastes electricity? (a) switch off empty rooms (b) unplug idle chargers (c) set the AC to 24 °C (d) leave the TV on standby
15. 15.⚡ A device works on 5 V and takes 1 A. What is its power (in watts)? =
16. 16.🧾 A family uses 120 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
17. 17.🧮 A 2 V battery is joined to 5 Ω and 3 Ω resistors in series. What current flows (in amperes)? =
18. 18.True or false: to iron one shirt at a time saves electricity. (a) True (b) False
19. 19.🌈 Which band is read first on a resistor? (a) any band (b) the widest gap (c) the gold band (d) the one nearest an end
20. 20.🧮 Two equal 330 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
21. 21.🧮 Two equal 50 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
22. 22.🔺 A 60 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
23. 23.⚡ A device works on 5 V and takes 0.25 A. What is its power (in watts)? =
24. 24.🧮 A 470 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)?
25. 25.⚡ A home appliance on the 230 V mains takes 10 A. What is its power (in watts)?
26. 26.🔺 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
27. 27.🔺 A current of 1 A flows when 15 V is joined across a resistor. What is its resistance (in ohms)?
28. 28.⚡ A device works on 1.5 V and takes 0.25 A. What is its power (in watts)? =
29. 29.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V ÷ I (c) P = V + I (d) P = V × I
30. 30.🌈 In the resistor colour code, which number does black stand for?
31. 31.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
32. 32.🔺 In the V-I-R triangle, how do we find R? (a) R = V + I (b) R = I ÷ V (c) R = V × I (d) R = V ÷ I
33. 33.🔺 A 23.5 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
34. 34.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
35. 35.🔺 A current of 2 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
36. 36.🧮 A 47 Ω resistor is joined in series with two equal 40 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
37. 37.🧮 A 470 Ω resistor is joined in series with two equal 470 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
38. 38.🌈 A resistor has the colour bands red, orange, yellow. What is its value in kilo-ohms (kΩ)? =
39. 39.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 46000 Ω resistor? (a) yellow-blue-red (b) yellow-blue-yellow (c) yellow-blue-orange (d) blue-yellow-orange
40. 40.📏 Which unit measures the push of a cell? (a) ampere (A) (b) volt (V) (c) ohm (Ω) (d) watt (W)

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