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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 575 · 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.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
  2. 2.🔦 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) Yes (b) No
  3. 3.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) one loose end (d) a complete loop
  4. 4.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  5. 5.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) it does not matter (c) both of them (d) only one
  6. 6.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
  7. 7.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the base (d) the glass
  8. 8.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
  9. 9.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  10. 10.🔦 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 metal paper clip. Does the bulb glow? (a) Yes (b) No
  11. 11.🔦 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
  12. 12.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
  13. 13.Which of these means the circuit is closed? (a) the switch is OFF (b) all wires are joined (c) the bulb is unscrewed (d) a wire has come loose
  14. 14.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  15. 15.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  16. 16.🔦 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 metal paper clip. Does the bulb glow? (a) Yes (b) No
  17. 17.🔦 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 steel coin. Does the bulb glow? (a) Yes (b) No
  18. 18.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
  19. 19.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) a wire is cut (d) the loop is complete
  20. 20.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
  21. 21.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
  22. 22.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
  23. 23.🔦 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 a safety pin. Does the bulb glow? (a) Yes (b) No
  24. 24.Which of these means the circuit is open? (a) a wire has come loose (b) all wires are joined (c) the loop is complete (d) the switch is ON
  25. 25.🔦 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 a rubber band. Does the bulb glow? (a) Yes (b) No
  26. 26.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  27. 27.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire has come loose (c) the bulb is unscrewed (d) the switch is ON
  28. 28.🔦 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
  29. 29.🔦 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 plastic ruler. Does the bulb glow? (a) Yes (b) No
  30. 30.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
  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 paper strip. Does the bulb glow? (a) Yes (b) No
  32. 32.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
  33. 33.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  34. 34.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. Does the bulb glow? (a) Yes (b) No
  35. 35.🔦 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) Yes (b) No
  36. 36.🔦 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 copper wire. Does the bulb glow? (a) No (b) Yes
  37. 37.🔦 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 cotton thread. Does the bulb glow? (a) Yes (b) No
  38. 38.🔦 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 cotton thread. Does the bulb glow? (a) No (b) Yes
  39. 39.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  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 paper strip. Does the bulb glow? (a) No (b) Yes

Answer key

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

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