← Open and closed circuits lesson New set →

Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 892 · 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.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a complete loop (d) a plastic gap
  2. 2.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
  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 steel coin. 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.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  6. 6.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
  7. 7.🔦 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) Yes (b) No
  8. 8.Which of these means the circuit is closed? (a) a cell is taken out (b) the loop is complete (c) a wire has come loose (d) the switch is OFF
  9. 9.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) the switch is OFF
  10. 10.Which of these means the circuit is closed? (a) a wire is cut (b) a cell is taken out (c) the bulb is unscrewed (d) the switch is ON
  11. 11.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
  12. 12.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  13. 13.🔦 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 dry cork. Does the bulb glow? (a) Yes (b) No
  14. 14.🔦 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
  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 an iron nail. Does the bulb glow? (a) Yes (b) No
  16. 16.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
  17. 17.🔦 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 dry cork. Does the bulb glow? (a) Yes (b) No
  18. 18.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
  19. 19.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
  20. 20.🔦 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
  21. 21.🔦 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) Yes (b) No
  22. 22.🔦 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) Yes (b) No
  23. 23.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  24. 24.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) none (c) only one (d) it does not matter
  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. Does the bulb glow? (a) Yes (b) No
  26. 26.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  27. 27.Which of these means the circuit is closed? (a) a wire has come loose (b) all wires are joined (c) a wire is cut (d) the switch is OFF
  28. 28.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the base (d) the switch
  29. 29.🔦 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 copper wire. Does the bulb glow? (a) No (b) Yes
  30. 30.🔦 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
  31. 31.🔦 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 dry cork. Does the bulb glow? (a) Yes (b) No
  32. 32.Which of these means the circuit is open? (a) the loop is complete (b) the bulb is unscrewed (c) the switch is ON (d) all wires are joined
  33. 33.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a series circuit (c) a closed circuit (d) an open circuit
  34. 34.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
  35. 35.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
  36. 36.🔦 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
  37. 37.True or false: if the switch is OFF, the circuit is closed and 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 dry cork. Does the bulb glow? (a) No (b) Yes
  39. 39.🔦 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
  40. 40.🔦 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

Answer key

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

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