Electronics Worksheet: Components and Ohm’s Law Test

Electronics lesson 20: Part 2 test: components and Ohm’s law · Set 297 · 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.🧩 Which part changes electrical energy into movement? (a) a fuse (b) a motor (c) an LED (d) a resistor
2. 2.📏 Voltmeter or ammeter: which one is joined across a part? (a) voltmeter (b) ammeter
3. 3.🔺 A 16.5 V supply is joined across a 330 Ω resistor. What current flows (in milliamperes, mA)?
4. 4.🧩 Which part changes electrical energy into sound? (a) a diode (b) a resistor (c) a capacitor (d) a buzzer
5. 5.🔺 A current of 10 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
6. 6.📏 Which unit measures how much a part resists? (a) ampere (A) (b) volt (V) (c) watt (W) (d) ohm (Ω)
7. 7.🧩 Which component makes a beeping sound? (a) capacitor (b) LDR (c) diode (d) buzzer
8. 8.📏 In the water-pipe picture of a circuit, voltage is like … (a) the water pressure (b) the water tank lid (c) the pipe colour (d) the tap handle
9. 9.True or false: on an LED, the shorter leg is the anode (+). (a) False (b) True
10. 10.🔺 A 24 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
11. 11.🌈 Which band is read first on a resistor? (a) the gold band (b) any band (c) the one nearest an end (d) the widest gap
12. 12.🔺 A current of 50 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
13. 13.🔺 A current of 1 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
14. 14.🌈 In the resistor colour code, which number does black stand for?
15. 15.🔺 A current of 0.25 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
16. 16.🔺 A current of 0.1 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
17. 17.🔺 A 12 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
18. 18.⚡ A 1.5 W device works on 6 V. What current does it take (in amperes)? =
19. 19.🔺 A current of 0.5 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
20. 20.📏 How many kilowatts (kW) is 1100 W? =
21. 21.📏 How many milliamperes (mA) make 1 ampere? (a) 1000 (b) 60 (c) 10 (d) 100
22. 22.True or false: on an LED, the round-side leg is the anode (+). (a) False (b) True
23. 23.Which of these wastes electricity? (a) close the fridge quickly (b) leave the TV on standby (c) switch off empty rooms (d) unplug idle chargers
24. 24.🧩 Which component limits the current? (a) LED (b) fuse (c) resistor (d) buzzer
25. 25.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) gets smaller (c) stays the same (d) becomes zero
26. 26.True or false: the voltmeter is joined in series. (a) True (b) False
27. 27.🔍 Which is the odd one out? (a) run fans in empty rooms (b) close the fridge quickly (c) use old filament bulbs (d) iron one shirt at a time
28. 28.🔺 A current of 1 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
29. 29.🔺 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
30. 30.🧮 Two resistors in parallel give a total that is … (a) their sum (b) more than either one (c) always zero (d) less than either one
31. 31.🧩 Which component beeps for an alarm? (a) capacitor (b) LED (c) diode (d) buzzer
32. 32.🔺 A current of 0.5 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
33. 33.🧾 A family uses 50 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
34. 34.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
35. 35.🧮 A 220 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)?
36. 36.True or false: a potentiometer makes things spin. (a) True (b) False
37. 37.True or false: the push of a cell is measured in amperes (A). (a) True (b) False
38. 38.🔺 A current of 2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
39. 39.📏 How many ohms (Ω) is 8.6 kΩ?
40. 40.Which of these saves electricity? (a) use LED lamps (b) leave fridge door open (c) iron one shirt at a time (d) leave the TV on standby

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