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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 828 · 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) all wires are joined (b) a cell is taken out (c) the loop is complete (d) the switch is ON
  2. 2.🔁 What must there be for a current to flow? (a) a complete loop (b) a plastic gap (c) a broken path (d) one loose end
  3. 3.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is OFF (c) the switch is ON (d) a wire has come loose
  4. 4.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) a wire has come loose (d) the switch is ON
  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 ceramic cup. Does the bulb glow? (a) No (b) Yes
  6. 6.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  7. 7.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
  8. 8.Which of these means the circuit is closed? (a) all wires are joined (b) the bulb is unscrewed (c) a wire has come loose (d) the switch is OFF
  9. 9.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  10. 10.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) a wire is cut (d) all wires are joined
  11. 11.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  12. 12.🔦 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
  13. 13.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  14. 14.🔦 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
  15. 15.🔦 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 ceramic cup. Does the bulb glow? (a) No (b) Yes
  16. 16.🔁 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
  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 brass key. 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 an iron nail. Does the bulb glow? (a) No (b) Yes
  19. 19.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the filament (d) the base
  20. 20.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
  21. 21.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
  22. 22.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
  23. 23.🔦 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
  24. 24.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
  25. 25.🔦 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 dry cork. Does the bulb glow? (a) No (b) Yes
  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 spoon. Does the bulb glow? (a) No (b) Yes
  27. 27.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  28. 28.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  29. 29.🔦 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) No (b) Yes
  30. 30.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
  31. 31.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
  32. 32.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
  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 aluminium foil. Does the bulb glow? (a) Yes (b) No
  34. 34.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
  35. 35.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  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) Yes (b) No
  37. 37.Which of these means the circuit is open? (a) the loop is complete (b) the bulb is unscrewed (c) the switch is ON (d) all wires are joined
  38. 38.🔦 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 steel spoon. Does the bulb glow? (a) Yes (b) No
  39. 39.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the switch is OFF (d) the loop is complete
  40. 40.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No

Answer key

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

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