← Open and closed circuits lesson New set →

Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 906 · 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.

NameDateTime takenScore ___ / 40
  1. 1.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
  2. 2.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  3. 3.🔦 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 rubber eraser. Does the bulb glow? (a) No (b) Yes
  4. 4.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  5. 5.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
  6. 6.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  7. 7.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  8. 8.🔦 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 dry cork. Does the bulb glow? (a) Yes (b) No
  9. 9.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
  10. 10.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) a wire is cut
  11. 11.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) none (c) it does not matter (d) only one
  12. 12.Which of these means the circuit is open? (a) the switch is ON (b) a cell is taken out (c) all wires are joined (d) the loop is complete
  13. 13.🔦 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 glass marble. Does the bulb glow? (a) No (b) Yes
  14. 14.🔦 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 spoon. Does the bulb glow? (a) No (b) Yes
  15. 15.🔦 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 woollen thread. Does the bulb glow? (a) Yes (b) No
  16. 16.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the base (d) the switch
  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 paper strip. Does the bulb glow? (a) No (b) Yes
  18. 18.Which of these means the circuit is closed? (a) a wire has come loose (b) the loop is complete (c) a wire is cut (d) the bulb is unscrewed
  19. 19.🔦 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 wooden stick. Does the bulb glow? (a) No (b) Yes
  20. 20.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
  21. 21.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
  22. 22.Which of these means the circuit is closed? (a) a wire is cut (b) a wire has come loose (c) a cell is taken out (d) the switch is ON
  23. 23.🔦 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
  24. 24.🔁 What must there be for a current to flow? (a) a complete loop (b) a plastic gap (c) a broken path (d) one loose end
  25. 25.🔦 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
  26. 26.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
  27. 27.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  28. 28.🔦 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 ruler. 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. One wire has come loose from the cell. Does the bulb glow? (a) Yes (b) No
  30. 30.🔦 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 rubber eraser. Does the bulb glow? (a) Yes (b) No
  31. 31.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  32. 32.Which of these means the circuit is closed? (a) a cell is taken out (b) all wires are joined (c) a wire is cut (d) the bulb is unscrewed
  33. 33.🔦 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
  34. 34.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
  35. 35.🔦 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
  36. 36.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  37. 37.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
  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 plastic ruler. Does the bulb glow? (a) Yes (b) No
  39. 39.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
  40. 40.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False

Answer key

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

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids