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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 543 · 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.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 has come loose
  2. 2.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
  3. 3.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  4. 4.🔦 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
  5. 5.🔦 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
  6. 6.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
  7. 7.🔁 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
  8. 8.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the filament (d) the base
  9. 9.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
  10. 10.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  11. 11.Which of these means the circuit is closed? (a) a wire has come loose (b) a wire is cut (c) the switch is OFF (d) the loop is complete
  12. 12.🔦 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 wooden stick. Does the bulb glow? (a) No (b) Yes
  13. 13.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
  14. 14.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the switch is OFF (d) the loop is complete
  15. 15.Which of these means the circuit is closed? (a) the switch is OFF (b) all wires are joined (c) a wire is cut (d) a wire has come loose
  16. 16.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  17. 17.🔦 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
  18. 18.🔦 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
  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 ceramic cup. Does the bulb glow? (a) No (b) Yes
  20. 20.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a broken path (d) a complete loop
  21. 21.🔁 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
  22. 22.🔦 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) No (b) Yes
  23. 23.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
  24. 24.🔦 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
  25. 25.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  26. 26.🔦 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
  27. 27.🔦 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 ceramic cup. Does the bulb glow? (a) No (b) Yes
  28. 28.🔦 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 woollen thread. Does the bulb glow? (a) No (b) Yes
  29. 29.🔦 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
  30. 30.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
  31. 31.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
  32. 32.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
  33. 33.🔦 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
  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 plastic straw. Does the bulb glow? (a) Yes (b) No
  35. 35.Which of these means the circuit is closed? (a) a wire has come loose (b) the bulb is unscrewed (c) a wire is cut (d) the switch is ON
  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) Yes (b) No
  37. 37.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
  38. 38.🔦 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
  39. 39.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
  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. A gap in one wire is bridged by a rubber eraser. Does the bulb glow? (a) Yes (b) No

Answer key

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

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