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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 311 · 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 do we call a circuit with a break in it? (a) a series circuit (b) a closed circuit (c) an open circuit (d) a full circuit
  2. 2.Which of these means the circuit is closed? (a) a cell is taken out (b) the bulb is unscrewed (c) all wires are joined (d) a wire is cut
  3. 3.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a plastic gap (d) a complete loop
  4. 4.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  5. 5.🔦 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
  6. 6.🔦 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
  7. 7.🔦 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 graphite rod. Does the bulb glow? (a) No (b) Yes
  8. 8.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
  9. 9.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  10. 10.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  11. 11.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the loop is complete (c) a wire has come loose (d) a wire is cut
  12. 12.🔦 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 plastic ruler. 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) False (b) True
  14. 14.Which of these means the circuit is open? (a) the switch is OFF (b) all wires are joined (c) the loop is complete (d) the switch is ON
  15. 15.🔦 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) Yes (b) No
  16. 16.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the base (d) the switch
  17. 17.Which of these means the circuit is open? (a) a cell is taken out (b) the switch is ON (c) the loop is complete (d) all wires are joined
  18. 18.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  19. 19.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  20. 20.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  21. 21.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) the bulb is unscrewed
  22. 22.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
  23. 23.🔦 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 paper strip. Does the bulb glow? (a) Yes (b) No
  24. 24.🔦 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
  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 wooden stick. Does the bulb glow? (a) No (b) Yes
  26. 26.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a wire is cut (d) the switch is ON
  27. 27.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is OFF (c) a wire has come loose (d) the switch is ON
  28. 28.🔦 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) No (b) Yes
  29. 29.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
  30. 30.🔦 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 ruler. Does the bulb glow? (a) Yes (b) No
  31. 31.🔦 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
  32. 32.🔦 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
  33. 33.🔦 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
  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 aluminium foil. Does the bulb glow? (a) Yes (b) No
  35. 35.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
  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 steel coin. Does the bulb glow? (a) No (b) Yes
  37. 37.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
  38. 38.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
  39. 39.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  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 woollen thread. Does the bulb glow? (a) Yes (b) No

Answer key

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

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