← Open and closed circuits lesson New set →

Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 665 · 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.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the base (c) the glass (d) the filament
  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) Yes (b) No
  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 cotton thread. Does the bulb glow? (a) No (b) Yes
  4. 4.Which of these means the circuit is closed? (a) the switch is OFF (b) the switch is ON (c) a wire has come loose (d) a cell is taken out
  5. 5.Which of these means the circuit is closed? (a) all wires are joined (b) a wire has come loose (c) the switch is OFF (d) the bulb is unscrewed
  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 all wires are joined? (a) open (b) closed
  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. Does the bulb glow? (a) No (b) Yes
  9. 9.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
  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) Yes (b) No
  11. 11.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  12. 12.🔦 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
  13. 13.🔁 What must there be for a current to flow? (a) a complete loop (b) a broken path (c) one loose end (d) a plastic gap
  14. 14.Which of these means the circuit is open? (a) the loop is complete (b) a wire is cut (c) all wires are joined (d) the switch is ON
  15. 15.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  16. 16.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  17. 17.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 cell is taken out
  18. 18.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
  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 an iron nail. Does the bulb glow? (a) Yes (b) No
  20. 20.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
  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 glass marble. Does the bulb glow? (a) Yes (b) No
  22. 22.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  23. 23.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) it does not matter (c) none (d) only one
  24. 24.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
  25. 25.🔦 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) No (b) Yes
  26. 26.🔦 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 spoon. Does the bulb glow? (a) Yes (b) No
  27. 27.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a full circuit (c) an open circuit (d) a closed circuit
  28. 28.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
  29. 29.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
  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 rubber band. Does the bulb glow? (a) No (b) Yes
  31. 31.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
  32. 32.🔦 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 paper strip. Does the bulb glow? (a) No (b) Yes
  33. 33.🔦 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
  34. 34.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
  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 a metal paper clip. Does the bulb glow? (a) Yes (b) No
  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) No (b) Yes
  37. 37.Which of these means the circuit is open? (a) a wire has come loose (b) the switch is ON (c) the loop is complete (d) all wires are joined
  38. 38.🔦 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 glass marble. Does the bulb glow? (a) Yes (b) No
  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 brass key. Does the bulb glow? (a) Yes (b) No
  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 cotton thread. Does the bulb glow? (a) No (b) Yes

Answer key

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

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