Electronics Worksheet: Components and Ohm’s Law Test

Electronics lesson 20: Part 2 test: components and Ohm’s law · Set 396 · 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 unit measures the push of a cell? (a) ampere (A) (b) watt (W) (c) volt (V) (d) ohm (Ω)
2. 2.True or false: on an LED, the round-side leg is the cathode (−). (a) False (b) True
3. 3.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
4. 4.🌈 In the resistor colour code, which number does brown stand for?
5. 5.🌈 A resistor has the colour bands white, orange, brown. What is its value (in ohms)?
6. 6.📏 In the water-pipe picture of a circuit, current is like … (a) the water pressure (b) the flow of water (c) a narrow pipe (d) the pipe colour
7. 7.🌈 A resistor has the colour bands brown, red, red. What is its value (in ohms)?
8. 8.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 40 Ω resistor? (a) yellow-black-brown (b) green-black-black (c) yellow-black-black (d) green-yellow-black
9. 9.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
10. 10.🔺 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
11. 11.📏 Voltmeter or ammeter: which one is joined in series? (a) ammeter (b) voltmeter
12. 12.What does a potentiometer do? (a) lets current go one way (b) blows if current is high (c) is a resistance knob (d) makes a beeping sound
13. 13.🔺 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
14. 14.🧩 Which component has coloured bands? (a) thermistor (b) transistor (c) buzzer (d) resistor
15. 15.📏 How many watts (W) is 0.3 kW?
16. 16.⚡ A device works on 6 V and takes 1.5 A. What is its power (in watts)? =
17. 17.True or false: the ammeter is joined in series. (a) False (b) True
18. 18.📏 How many kilo-ohms (kΩ) is 1600 Ω? =
19. 19.💡 What happens if an LED is put in backwards? (a) it does not light (b) it changes colour (c) it makes a sound (d) it lights brighter
20. 20.🔺 A current of 50 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
21. 21.🔺 A 2 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
22. 22.📏 How many milliamperes (mA) is 0.02 A?
23. 23.True or false: an LED makes a beeping sound. (a) False (b) True
24. 24.🔺 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
25. 25.Which of these is measured in watts (W)? (a) resistance (b) the push of a cell (c) energy used each second (d) current
26. 26.📏 In the water-pipe picture of a circuit, voltage is like … (a) the water tank lid (b) the pipe colour (c) the water pressure (d) the tap handle
27. 27.🔺 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
28. 28.🔺 A current of 25 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
29. 29.📏 Which unit measures the flow of charge? (a) watt (W) (b) ohm (Ω) (c) ampere (A) (d) volt (V)
30. 30.Which of these saves electricity? (a) run fans in empty rooms (b) leave fridge door open (c) use old filament bulbs (d) close the fridge quickly
31. 31.🌈 A resistor has the colour bands brown, black, orange. What is its value in kilo-ohms (kΩ)? =
32. 32.True or false: the voltmeter measures voltage. (a) False (b) True
33. 33.🔺 A current of 2.5 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
34. 34.🌈 A resistor has the colour bands orange, red, red. What is its value in kilo-ohms (kΩ)? =
35. 35.⚡ A 0.6 W device works on 6 V. What current does it take (in amperes)? =
36. 36.🔺 A current of 2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
37. 37.🔍 Which is the odd one out? (a) leave the TV on standby (b) run fans in empty rooms (c) leave fridge door open (d) use daylight to read
38. 38.⚡ Power tells us … (a) energy used each second (b) the colour of light (c) the length of a wire (d) the size of a cell
39. 39.🔺 A current of 40 mA flows when 8.8 V is joined across a resistor. What is its resistance (in ohms)?
40. 40.🌈 A resistor has the colour bands orange, orange, yellow. What is its value in kilo-ohms (kΩ)? =

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