← Open and closed circuits lesson New set →

Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 344 · 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.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  2. 2.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) one loose end (d) a plastic gap
  3. 3.Which of these means the circuit is closed? (a) a wire has come loose (b) a wire is cut (c) the loop is complete (d) the bulb is unscrewed
  4. 4.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
  5. 5.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
  6. 6.🔦 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 plastic ruler. Does the bulb glow? (a) Yes (b) No
  7. 7.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) both of them (c) it does not matter (d) only one
  8. 8.🔦 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
  9. 9.🔦 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 steel coin. Does the bulb glow? (a) Yes (b) No
  10. 10.🔦 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) No (b) Yes
  11. 11.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
  12. 12.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the switch is ON (c) the loop is complete (d) all wires are joined
  13. 13.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
  14. 14.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) a cell is taken out (d) all wires are joined
  15. 15.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is ON (c) a wire has come loose (d) a wire is cut
  16. 16.🔦 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
  17. 17.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) the switch is OFF
  18. 18.🔦 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
  19. 19.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  20. 20.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the base (d) the switch
  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 a graphite rod. Does the bulb glow? (a) No (b) Yes
  22. 22.🔦 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) No (b) Yes
  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 a cotton thread. Does the bulb glow? (a) Yes (b) No
  24. 24.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
  25. 25.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
  26. 26.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
  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 metal paper clip. Does the bulb glow? (a) Yes (b) No
  28. 28.🔦 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) Yes (b) No
  29. 29.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  30. 30.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  31. 31.🔦 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
  32. 32.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
  33. 33.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  34. 34.🔦 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 woollen thread. Does the bulb glow? (a) No (b) Yes
  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 an iron nail. Does the bulb glow? (a) No (b) Yes
  36. 36.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
  37. 37.🔦 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) Yes (b) No
  38. 38.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
  39. 39.🔦 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) Yes (b) No
  40. 40.🔦 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 plastic straw. Does the bulb glow? (a) Yes (b) No

Answer key

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

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