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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 840 · 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.

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  1. 1.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) none (c) it does not matter (d) both of them
  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 glass marble. Does the bulb glow? (a) Yes (b) No
  3. 3.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is OFF (c) all wires are joined (d) a cell is taken out
  4. 4.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a series circuit (d) a full circuit
  5. 5.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
  6. 6.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  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 wooden stick. Does the bulb glow? (a) Yes (b) No
  8. 8.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
  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 safety pin. Does the bulb glow? (a) Yes (b) No
  10. 10.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  11. 11.🔦 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
  12. 12.🔦 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
  13. 13.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the bulb is unscrewed (d) the loop is complete
  14. 14.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  15. 15.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  16. 16.🔦 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
  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 plastic straw. 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 an iron nail. Does the bulb glow? (a) Yes (b) No
  20. 20.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  21. 21.Which of these means the circuit is open? (a) all wires are joined (b) a wire is cut (c) the switch is ON (d) the loop is complete
  22. 22.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) a plastic gap (d) one loose end
  23. 23.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
  24. 24.Which of these means the circuit is open? (a) all wires are joined (b) a wire has come loose (c) the switch is ON (d) the loop is complete
  25. 25.🔦 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
  26. 26.Which of these means the circuit is open? (a) a cell is taken out (b) all wires are joined (c) the switch is ON (d) the loop is complete
  27. 27.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
  28. 28.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
  29. 29.🔦 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
  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 woollen thread. Does the bulb glow? (a) No (b) Yes
  31. 31.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
  32. 32.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire is cut (c) a cell is taken out (d) the switch is ON
  33. 33.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
  34. 34.True or false: if the bulb is unscrewed, 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 ceramic cup. Does the bulb glow? (a) No (b) Yes
  36. 36.🔦 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
  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 copper wire. Does the bulb glow? (a) No (b) Yes
  38. 38.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  39. 39.🔦 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 paper strip. 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. All the wires are firmly joined. A gap in one wire is bridged by a dry cork. Does the bulb glow? (a) Yes (b) No

Answer key

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

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