← Open and closed circuits lesson New set →

Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 292 · 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) True (b) False
  2. 2.Which of these means the circuit is closed? (a) a wire is cut (b) all wires are joined (c) the bulb is unscrewed (d) the switch is OFF
  3. 3.🔁 What must there be for a current to flow? (a) a complete loop (b) one loose end (c) a broken path (d) a plastic gap
  4. 4.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a cell is taken out
  5. 5.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
  6. 6.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  7. 7.🔦 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
  8. 8.🔦 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) No (b) Yes
  9. 9.🔦 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
  10. 10.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) an open circuit (d) a series circuit
  11. 11.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  12. 12.Which of these means the circuit is closed? (a) the loop is complete (b) a wire is cut (c) a wire has come loose (d) a cell is taken out
  13. 13.🔦 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) No (b) Yes
  14. 14.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
  15. 15.True or false: if a wire is cut, 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 woollen thread. Does the bulb glow? (a) No (b) Yes
  17. 17.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
  18. 18.True or false: if a wire has come loose, 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. Does the bulb glow? (a) Yes (b) No
  20. 20.🔦 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
  21. 21.🔦 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
  22. 22.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the filament (d) the base
  23. 23.🔦 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
  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 plastic ruler. Does the bulb glow? (a) Yes (b) No
  25. 25.🔦 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) Yes (b) No
  26. 26.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
  27. 27.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) none (d) both of them
  28. 28.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  29. 29.🔦 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 rubber band. Does the bulb glow? (a) Yes (b) No
  30. 30.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
  31. 31.Which of these means the circuit is closed? (a) the switch is ON (b) the bulb is unscrewed (c) a wire is cut (d) a wire has come loose
  32. 32.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  33. 33.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
  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 graphite rod. 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 a steel coin. Does the bulb glow? (a) Yes (b) No
  36. 36.🔦 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 cotton thread. Does the bulb glow? (a) No (b) Yes
  37. 37.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 bulb is unscrewed
  38. 38.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
  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 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. One wire has come loose from the cell. Does the bulb glow? (a) No (b) Yes

Answer key

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

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