← Open and closed circuits lesson New set →

Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 881 · 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 the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
  2. 2.🔦 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
  3. 3.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the base (d) the switch
  4. 4.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
  5. 5.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) a wire is cut
  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 plastic straw. Does the bulb glow? (a) No (b) Yes
  7. 7.🔦 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
  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) Yes (b) No
  9. 9.True or false: if all wires are joined, 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 OFF. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
  11. 11.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) the switch is OFF
  12. 12.🔦 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) No (b) Yes
  13. 13.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 has come loose
  14. 14.Which of these means the circuit is closed? (a) a cell is taken out (b) the loop is complete (c) a wire is cut (d) the bulb is unscrewed
  15. 15.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a full circuit (d) a series circuit
  16. 16.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  17. 17.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
  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 woollen thread. Does the bulb glow? (a) No (b) Yes
  19. 19.Which of these means the circuit is closed? (a) the switch is OFF (b) a cell is taken out (c) all wires are joined (d) a wire is cut
  20. 20.🔁 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
  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 rubber eraser. Does the bulb glow? (a) Yes (b) No
  22. 22.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is ON (c) the bulb is unscrewed (d) a cell is taken out
  23. 23.🔦 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
  24. 24.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
  25. 25.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  26. 26.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  27. 27.🔦 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
  28. 28.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
  29. 29.🔦 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
  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 plastic ruler. Does the bulb glow? (a) No (b) Yes
  31. 31.🔦 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) Yes (b) No
  32. 32.🔁 What must there be for a current to flow? (a) a plastic gap (b) a broken path (c) one loose end (d) a complete loop
  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 brass key. Does the bulb glow? (a) No (b) Yes
  34. 34.🔦 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) No (b) Yes
  35. 35.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
  36. 36.🔦 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) No (b) Yes
  37. 37.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  38. 38.🔦 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
  39. 39.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
  40. 40.🔦 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) No (b) Yes

Answer key

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

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