Electronics Worksheet: Components and Ohm’s Law Test

Electronics lesson 20: Part 2 test: components and Ohm’s law · Set 874 · 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 current of 10 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
2. 2.True or false: resistance is measured in watts (W). (a) False (b) True
3. 3.What does a buzzer do? (a) has coloured bands (b) is a resistance knob (c) boosts a small signal (d) beeps for an alarm
4. 4.🔺 A current of 10 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
5. 5.🌈 A resistor has the colour bands yellow, red, brown. What is its value (in ohms)?
6. 6.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) their sum (c) less than either one (d) always zero
7. 7.🧩 A capacitor in a circuit can … (a) spin a wheel (b) store charge briefly (c) measure heat (d) make light
8. 8.True or false: the flow of charge is measured in amperes (A). (a) True (b) False
9. 9.🔺 A 2.5 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
10. 10.Which of these is measured in ohms (Ω)? (a) resistance (b) energy used each second (c) the flow of charge (d) the push of a cell
11. 11.📏 Voltmeter or ammeter: which one is joined across a part? (a) ammeter (b) voltmeter
12. 12.🔍 Which is the odd one out? (a) use LED lamps (b) leave fridge door open (c) use daylight to read (d) unplug idle chargers
13. 13.🧾 A family uses 50 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
14. 14.🌈 In the resistor colour code, which number does blue stand for?
15. 15.🧮 Four equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
16. 16.Which of these is measured in ohms (Ω)? (a) the push of a cell (b) voltage (c) the flow of charge (d) how much a part resists
17. 17.🧮 A 150 Ω resistor is joined in series with two equal 100 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
18. 18.🌈 A resistor has the colour bands blue, white, red. What is its value in kilo-ohms (kΩ)? =
19. 19.🌈 A resistor has the colour bands green, brown, orange. What is its value (in ohms)?
20. 20.🔍 Which is the odd one out? (a) leave fridge door open (b) run fans in empty rooms (c) set the AC to 24 °C (d) iron one shirt at a time
21. 21.Which of these is measured in watts (W)? (a) the push of a cell (b) resistance (c) voltage (d) power
22. 22.🔺 A current of 20 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
23. 23.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) stays the same (c) gets smaller (d) becomes zero
24. 24.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V + R (c) I = V × R (d) I = R ÷ V
25. 25.🧩 Which component senses how hot it is? (a) fuse (b) LED (c) resistor (d) thermistor
26. 26.⚡ Which formula gives electric power? (a) P = V × I (b) P = V ÷ I (c) P = I ÷ V (d) P = V + I
27. 27.🧮 A 1.1 V battery is joined to 3 Ω and 8 Ω resistors in series. What current flows (in amperes)? =
28. 28.🔺 A current of 25 mA flows when 2.5 V is joined across a resistor. What is its resistance (in ohms)?
29. 29.🧩 Which component glows using little power? (a) thermistor (b) LED (c) motor (d) capacitor
30. 30.True or false: a buzzer boosts a small signal. (a) True (b) False
31. 31.🔺 A current of 50 mA flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
32. 32.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 50 % (c) 25 % (d) 5 %
33. 33.🧩 Which part changes electrical energy into sound? (a) a diode (b) a resistor (c) a buzzer (d) a capacitor
34. 34.🔺 A current of 2.5 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
35. 35.💡 What happens if an LED is put in backwards? (a) it makes a sound (b) it lights brighter (c) it does not light (d) it changes colour
36. 36.⚡ Power tells us … (a) the colour of light (b) the length of a wire (c) the size of a cell (d) energy used each second
37. 37.🧾 A 200 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
38. 38.True or false: on an LED, the round-side leg is the anode (+). (a) False (b) True
39. 39.🧮 A 13 V battery is joined to 8 Ω and 5 Ω resistors in series. What current flows (in amperes)? =
40. 40.🔺 A 6.6 V supply is joined across a 330 Ω resistor. What current flows (in milliamperes, mA)?

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