← Open and closed circuits lesson New set →

Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 951 · 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.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is OFF (d) the switch is ON
  2. 2.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the glass (d) the switch
  3. 3.Which of these means the circuit is open? (a) all wires are joined (b) the bulb is unscrewed (c) the switch is ON (d) the loop is complete
  4. 4.🔁 Is the circuit closed or open if a wire is cut? (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. A gap in one wire is bridged by a copper wire. Does the bulb glow? (a) No (b) Yes
  6. 6.🔁 Is the circuit closed or open if all wires are joined? (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 brass key. Does the bulb glow? (a) No (b) Yes
  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) No (b) Yes
  9. 9.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 wire is cut
  10. 10.🔦 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) Yes (b) No
  11. 11.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a series circuit (c) a closed circuit (d) an open circuit
  12. 12.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a plastic gap (d) a complete loop
  13. 13.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
  14. 14.🔦 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 ceramic cup. Does the bulb glow? (a) Yes (b) No
  15. 15.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
  16. 16.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
  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 steel spoon. Does the bulb glow? (a) Yes (b) No
  18. 18.🔦 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
  19. 19.🔦 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) No (b) Yes
  20. 20.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
  21. 21.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
  22. 22.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  23. 23.True or false: if the switch is ON, 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 copper wire. Does the bulb glow? (a) No (b) Yes
  25. 25.🔦 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 straw. Does the bulb glow? (a) No (b) Yes
  26. 26.🔦 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
  27. 27.Which of these means the circuit is closed? (a) the switch is ON (b) a wire has come loose (c) the bulb is unscrewed (d) a wire is cut
  28. 28.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire has come loose (c) the loop is complete (d) the bulb is unscrewed
  29. 29.Which of these means the circuit is open? (a) the loop is complete (b) a wire has come loose (c) the switch is ON (d) all wires are joined
  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 steel coin. 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 graphite rod. Does the bulb glow? (a) Yes (b) No
  32. 32.🔦 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) No (b) Yes
  33. 33.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) both of them (c) none (d) it does not matter
  34. 34.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is OFF (c) the bulb is unscrewed (d) all wires are joined
  35. 35.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
  36. 36.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  37. 37.🔦 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) Yes (b) No
  38. 38.🔦 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 spoon. Does the bulb glow? (a) Yes (b) No
  39. 39.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
  40. 40.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False

Answer key

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

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