Electronics Worksheet: Components and Ohm’s Law Test

Electronics lesson 20: Part 2 test: components and Ohm’s law · Set 928 · 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 150 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)?
2. 2.What does a diode do? (a) blows if current is high (b) lets current go one way (c) senses how bright it is (d) glows using little power
3. 3.⚡ Power tells us … (a) the length of a wire (b) the colour of light (c) the size of a cell (d) energy used each second
4. 4.🌈 In the resistor colour code, which number does black stand for?
5. 5.🔺 A current of 0.5 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
6. 6.⚡ A device works on 24 V and takes 0.2 A. What is its power (in watts)? =
7. 7.🔺 A current of 10 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
8. 8.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
9. 9.📏 How many amperes (A) is 1810 mA? =
10. 10.⚡ A device works on 3 V and takes 3 A. What is its power (in watts)? =
11. 11.True or false: a potentiometer turns a fan or wheels. (a) False (b) True
12. 12.🧩 Which part changes electrical energy into sound? (a) a diode (b) a resistor (c) a capacitor (d) a buzzer
13. 13.📏 How many amperes (A) is 2010 mA? =
14. 14.🔺 A 4 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
15. 15.🔺 A 1 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
16. 16.Which of these is measured in volts (V)? (a) how much a part resists (b) the push of a cell (c) current (d) power
17. 17.🌈 Which band is read first on a resistor? (a) the widest gap (b) the one nearest an end (c) the gold band (d) any band
18. 18.🌈 In the resistor colour code, which number does brown stand for?
19. 19.🔺 A current of 50 mA flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
20. 20.Which of these wastes electricity? (a) use daylight to read (b) leave the TV on standby (c) close the fridge quickly (d) switch off empty rooms
21. 21.🔺 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
22. 22.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = I ÷ V (d) P = V × I
23. 23.🧩 Which component stores a little charge? (a) resistor (b) capacitor (c) motor (d) fuse
24. 24.🔺 A current of 10 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
25. 25.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 25 % (c) 50 % (d) 0 %
26. 26.🔍 Which is the odd one out? (a) switch off empty rooms (b) run fans in empty rooms (c) use daylight to read (d) set the AC to 24 °C
27. 27.🌈 In the resistor colour code, which number does blue stand for?
28. 28.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) stays the same (c) becomes zero (d) gets smaller
29. 29.🧩 Which component has coloured bands? (a) motor (b) capacitor (c) potentiometer (d) resistor
30. 30.🧾 A family uses 20 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
31. 31.True or false: on an LED, the round-side leg is the anode (+). (a) True (b) False
32. 32.🔺 A 2 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
33. 33.🌈 A resistor has the colour bands brown, orange, orange. What is its value in kilo-ohms (kΩ)? =
34. 34.🔺 A current of 0.1 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
35. 35.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
36. 36.Which of these is measured in amperes (A)? (a) energy used each second (b) voltage (c) current (d) how much a part resists
37. 37.🔺 A current of 50 mA flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
38. 38.True or false: a motor makes things spin. (a) False (b) True
39. 39.🧮 Two resistors in parallel give a total that is … (a) their sum (b) more than either one (c) less than either one (d) always zero
40. 40.🔺 An 8.8 V supply is joined across a 220 Ω resistor. What current flows (in milliamperes, mA)?

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