Electronics Worksheet: Components and Ohm’s Law Test

Electronics lesson 20: Part 2 test: components and Ohm’s law · Set 282 · 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.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) their sum (c) always zero (d) less than either one
2. 2.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a candle (c) an oil lamp (d) a filament bulb
3. 3.🧾 A family uses 50 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
4. 4.📏 In the water-pipe picture of a circuit, voltage is like … (a) the water tank lid (b) the pipe colour (c) the tap handle (d) the water pressure
5. 5.📏 How many ohms (Ω) is 1.9 kΩ?
6. 6.💡 An LED is joined to a 6 V battery through a 220 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) lights up (b) does not light (c) may burn out
7. 7.📏 Voltmeter or ammeter: which one measures voltage? (a) voltmeter (b) ammeter
8. 8.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = V ÷ I (c) R = V + I (d) R = I ÷ V
9. 9.🔺 A current of 0.5 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
10. 10.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
11. 11.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = I + R (c) V = I × R (d) V = R ÷ I
12. 12.📏 How many ohms (Ω) is 1.3 kΩ?
13. 13.🧮 Five equal 125 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
14. 14.True or false: a resistor makes a beeping sound. (a) True (b) False
15. 15.True or false: voltage is measured in ohms (Ω). (a) True (b) False
16. 16.🔍 Which is the odd one out? (a) close the fridge quickly (b) unplug idle chargers (c) iron one shirt at a time (d) switch off empty rooms
17. 17.💡 A blue LED uses 3 V and should get 20 mA. It runs from a 9 V supply. What resistor (in ohms) is needed in series?
18. 18.🔺 A current of 2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
19. 19.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = I ÷ V (d) P = V × I
20. 20.True or false: energy used each second is measured in ohms (Ω). (a) False (b) True
21. 21.💡 An LED is joined to a 3 V battery through a 330 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) lights up (b) may burn out (c) does not light
22. 22.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
23. 23.🌈 In the resistor colour code, which number does brown stand for?
24. 24.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 10 (b) 1024 (c) 1000 (d) 100
25. 25.True or false: a resistor limits the current. (a) False (b) True
26. 26.📏 Which unit measures resistance? (a) ohm (Ω) (b) ampere (A) (c) volt (V) (d) watt (W)
27. 27.🔺 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
28. 28.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
29. 29.🔺 An 8.25 V supply is joined across a 330 Ω resistor. What current flows (in milliamperes, mA)?
30. 30.📏 Voltmeter or ammeter: which one measures current? (a) ammeter (b) voltmeter
31. 31.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a capacitor (c) a resistor (d) a diode
32. 32.🔺 A current of 20 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
33. 33.⚡ A device works on 9 V and takes 2 A. What is its power (in watts)? =
34. 34.🌈 A resistor has the colour bands red, green, orange. What is its value (in ohms)?
35. 35.📏 Which unit measures the flow of charge? (a) volt (V) (b) ampere (A) (c) ohm (Ω) (d) watt (W)
36. 36.🔺 A current of 0.5 A flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
37. 37.🌈 In the resistor colour code, which number does violet stand for?
38. 38.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 94 Ω resistor? (a) brown-yellow-black (b) yellow-white-black (c) white-yellow-brown (d) white-yellow-black
39. 39.🔺 A current of 0.1 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
40. 40.⚡ A device works on 24 V and takes 1 A. What is its power (in watts)? =

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