← Open and closed circuits lesson New set →

Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 902 · 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 all wires are joined, the circuit is open and no current flows. (a) False (b) True
  2. 2.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  3. 3.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  4. 4.🔦 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 straw. Does the bulb glow? (a) Yes (b) No
  5. 5.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the filament (c) the base (d) the glass
  6. 6.🔦 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
  7. 7.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
  8. 8.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  9. 9.🔦 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 brass key. Does the bulb glow? (a) No (b) Yes
  10. 10.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
  11. 11.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a plastic gap (d) a broken path
  12. 12.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  13. 13.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
  14. 14.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) none (c) only one (d) both of them
  15. 15.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
  16. 16.🔦 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) Yes (b) No
  17. 17.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  18. 18.🔦 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) Yes (b) No
  19. 19.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) a wire has come loose
  20. 20.Which of these means the circuit is closed? (a) a cell is taken out (b) all wires are joined (c) a wire has come loose (d) a wire is cut
  21. 21.🔦 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 steel coin. Does the bulb glow? (a) No (b) Yes
  22. 22.Which of these means the circuit is open? (a) the switch is ON (b) a wire is cut (c) the loop is complete (d) all wires are joined
  23. 23.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  24. 24.🔦 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 ceramic cup. Does the bulb glow? (a) Yes (b) No
  25. 25.🔦 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
  26. 26.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
  27. 27.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  28. 28.🔦 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 safety pin. Does the bulb glow? (a) No (b) Yes
  29. 29.Which of these means the circuit is open? (a) all wires are joined (b) the switch is OFF (c) the switch is ON (d) the loop is complete
  30. 30.🔦 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
  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 a steel coin. Does the bulb glow? (a) No (b) Yes
  32. 32.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
  33. 33.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
  34. 34.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
  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 a woollen thread. Does the bulb glow? (a) No (b) Yes
  36. 36.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
  37. 37.🔦 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
  38. 38.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a series circuit (c) an open circuit (d) a closed circuit
  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 rubber band. 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 copper wire. Does the bulb glow? (a) Yes (b) No

Answer key

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

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