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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 371 · 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.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  2. 2.Which of these means the circuit is closed? (a) the switch is OFF (b) all wires are joined (c) a cell is taken out (d) a wire has come loose
  3. 3.🔦 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
  4. 4.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
  5. 5.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) a wire is cut
  6. 6.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
  7. 7.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) a wire is cut (d) the loop is complete
  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 ceramic cup. Does the bulb glow? (a) Yes (b) No
  9. 9.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
  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. A gap in one wire is bridged by a safety pin. Does the bulb glow? (a) Yes (b) No
  11. 11.🔦 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) No (b) Yes
  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 copper wire. Does the bulb glow? (a) Yes (b) No
  13. 13.🔦 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) No (b) Yes
  14. 14.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
  15. 15.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
  16. 16.🔁 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
  17. 17.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the glass (c) the filament (d) the switch
  18. 18.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
  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 metal paper clip. Does the bulb glow? (a) No (b) Yes
  20. 20.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  21. 21.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  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 switch is ON
  23. 23.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  24. 24.🔦 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) No (b) Yes
  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 ceramic cup. Does the bulb glow? (a) Yes (b) No
  26. 26.🔦 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
  27. 27.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  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 rubber band. Does the bulb glow? (a) No (b) Yes
  29. 29.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
  30. 30.🔁 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
  31. 31.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  32. 32.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
  33. 33.🔦 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
  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 ceramic cup. Does the bulb glow? (a) No (b) Yes
  35. 35.🔦 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) No (b) Yes
  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 graphite rod. Does the bulb glow? (a) No (b) Yes
  37. 37.🔦 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) Yes (b) No
  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 brass key. Does the bulb glow? (a) Yes (b) No
  39. 39.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
  40. 40.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False

Answer key

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

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