← Open and closed circuits lesson New set →

Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 851 · 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 loop is complete? (a) open (b) closed
  2. 2.🔦 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) No (b) Yes
  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. A gap in one wire is bridged by a copper wire. Does the bulb glow? (a) No (b) Yes
  4. 4.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
  5. 5.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) all wires are joined (c) a wire has come loose (d) a cell is taken out
  6. 6.🔦 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) No (b) Yes
  7. 7.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) an open circuit (c) a closed circuit (d) a full circuit
  8. 8.🔦 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
  9. 9.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
  10. 10.🔦 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
  11. 11.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the base (d) the filament
  12. 12.🔦 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 ceramic cup. Does the bulb glow? (a) Yes (b) No
  13. 13.Which of these means the circuit is open? (a) all wires are joined (b) a wire has come loose (c) the loop is complete (d) the switch is ON
  14. 14.🔁 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) only one (d) both of them
  15. 15.🔦 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 ruler. Does the bulb glow? (a) Yes (b) No
  16. 16.Which of these means the circuit is closed? (a) a wire has come loose (b) a wire is cut (c) the bulb is unscrewed (d) the switch is ON
  17. 17.🔦 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 woollen thread. Does the bulb glow? (a) No (b) Yes
  18. 18.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
  19. 19.Which of these means the circuit is closed? (a) the loop is complete (b) the switch is OFF (c) a cell is taken out (d) a wire has come loose
  20. 20.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
  21. 21.Which of these means the circuit is open? (a) the switch is ON (b) a wire is cut (c) all wires are joined (d) the loop is complete
  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. A gap in one wire is bridged by a steel coin. Does the bulb glow? (a) Yes (b) No
  23. 23.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
  24. 24.🔦 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
  25. 25.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
  26. 26.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
  27. 27.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
  28. 28.🔦 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
  29. 29.🔁 Is the circuit closed or open if the bulb is unscrewed? (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 a metal paper clip. Does the bulb glow? (a) Yes (b) No
  31. 31.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
  32. 32.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a broken path (d) a plastic gap
  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 wooden stick. Does the bulb glow? (a) No (b) Yes
  34. 34.🔦 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 ceramic cup. Does the bulb glow? (a) No (b) Yes
  35. 35.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  36. 36.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
  37. 37.🔦 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
  38. 38.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
  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) No (b) Yes
  40. 40.🔦 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

Answer key

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

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