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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 988 · 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.🔁 What must there be for a current to flow? (a) a plastic gap (b) a complete loop (c) one loose end (d) a broken path
  2. 2.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the switch is ON (c) all wires are joined (d) the loop is complete
  3. 3.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  4. 4.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  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 woollen thread. Does the bulb glow? (a) Yes (b) No
  6. 6.🔦 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
  7. 7.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  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 safety pin. Does the bulb glow? (a) Yes (b) No
  9. 9.🔦 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
  10. 10.🔦 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) No (b) Yes
  11. 11.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) it does not matter (c) only one (d) both of them
  12. 12.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
  13. 13.🔦 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
  14. 14.🔦 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) No (b) Yes
  15. 15.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
  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. A gap in one wire is bridged by a rubber eraser. Does the bulb glow? (a) No (b) Yes
  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 band. 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. 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
  19. 19.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) a wire has come loose
  20. 20.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
  21. 21.🔦 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) Yes (b) No
  22. 22.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire has come loose (c) the switch is OFF (d) the loop is complete
  23. 23.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
  24. 24.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
  25. 25.Which of these means the circuit is closed? (a) all wires are joined (b) the bulb is unscrewed (c) the switch is OFF (d) a cell is taken out
  26. 26.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  27. 27.🔦 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
  28. 28.🔦 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
  29. 29.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
  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 rubber eraser. 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 steel coin. Does the bulb glow? (a) Yes (b) No
  32. 32.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the filament (d) the base
  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 ceramic cup. Does the bulb glow? (a) No (b) Yes
  34. 34.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  35. 35.🔦 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) Yes (b) No
  36. 36.🔦 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) Yes (b) No
  37. 37.Which of these means the circuit is open? (a) the switch is OFF (b) the switch is ON (c) all wires are joined (d) the loop is complete
  38. 38.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  39. 39.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
  40. 40.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open

Answer key

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

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