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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 622 · 40 questions
TalentJR

Remember (Follow the loop): Closed circuit = complete loop = current flows; open circuit = a break = no current. Check every part: live cell, good bulb, switch ON, all wires joined, any gap bridged by a conductor. If even one check fails, the bulb does not glow.

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  1. 1.Which of these means the circuit is closed? (a) a wire has come loose (b) a cell is taken out (c) the loop is complete (d) the switch is OFF
  2. 2.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
  3. 3.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
  4. 4.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by an iron nail. Does the bulb glow? (a) No (b) Yes
  5. 5.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  6. 6.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a wooden stick. Does the bulb glow? (a) No (b) Yes
  7. 7.Which of these means the circuit is open? (a) the loop is complete (b) a cell is taken out (c) all wires are joined (d) the switch is ON
  8. 8.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) a complete loop (d) one loose end
  9. 9.Which of these means the circuit is open? (a) the switch is OFF (b) all wires are joined (c) the loop is complete (d) the switch is ON
  10. 10.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a wire has come loose
  11. 11.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  12. 12.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by aluminium foil. Does the bulb glow? (a) No (b) Yes
  13. 13.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the switch (d) the filament
  14. 14.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a steel spoon. Does the bulb glow? (a) Yes (b) No
  15. 15.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
  16. 16.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
  17. 17.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) a series circuit (d) an open circuit
  18. 18.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
  19. 19.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is OFF (c) the bulb is unscrewed (d) all wires are joined
  20. 20.Which of these means the circuit is closed? (a) a wire has come loose (b) a wire is cut (c) the switch is ON (d) the switch is OFF
  21. 21.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
  22. 22.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
  23. 23.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a plastic straw. Does the bulb glow? (a) No (b) Yes
  24. 24.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the loop is complete (c) the switch is ON (d) all wires are joined
  25. 25.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a brass key. Does the bulb glow? (a) Yes (b) No
  26. 26.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. A gap in one wire is bridged by an iron nail. Does the bulb glow? (a) Yes (b) No
  27. 27.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a woollen thread. Does the bulb glow? (a) No (b) Yes
  28. 28.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
  29. 29.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  30. 30.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by an iron nail. Does the bulb glow? (a) Yes (b) No
  31. 31.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a steel coin. Does the bulb glow? (a) No (b) Yes
  32. 32.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
  33. 33.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a metal paper clip. Does the bulb glow? (a) No (b) Yes
  34. 34.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  35. 35.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
  36. 36.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a dry cork. Does the bulb glow? (a) No (b) Yes
  37. 37.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
  38. 38.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
  39. 39.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a graphite rod. Does the bulb glow? (a) Yes (b) No
  40. 40.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a plastic straw. Does the bulb glow? (a) Yes (b) No

Answer key

  1. the loop is complete
  2. open
  3. No
  4. Yes
  5. open
  6. No
  7. a cell is taken out
  8. a complete loop
  9. the switch is OFF
  10. a wire has come loose
  11. open
  12. Yes
  13. the filament
  14. No
  15. False
  16. True
  17. an open circuit
  18. False
  19. all wires are joined
  20. the switch is ON
  21. True
  22. False
  23. No
  24. the bulb is unscrewed
  25. No
  26. No
  27. No
  28. True
  29. open
  30. No
  31. No
  32. False
  33. No
  34. closed
  35. Yes
  36. No
  37. False
  38. False
  39. No
  40. No

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