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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 377 · 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 the switch is OFF? (a) open (b) closed
  2. 2.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) the bulb is unscrewed
  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 graphite rod. Does the bulb glow? (a) Yes (b) No
  4. 4.Which of these means the circuit is closed? (a) all wires are joined (b) a wire has come loose (c) the bulb is unscrewed (d) the switch is OFF
  5. 5.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
  6. 6.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  7. 7.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  8. 8.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  9. 9.Which of these means the circuit is closed? (a) the loop is complete (b) a wire has come loose (c) the bulb is unscrewed (d) a cell is taken out
  10. 10.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
  11. 11.🔦 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 ruler. Does the bulb glow? (a) Yes (b) No
  12. 12.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the base (d) the switch
  13. 13.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is ON (c) a wire is cut (d) the switch is OFF
  14. 14.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
  15. 15.🔦 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
  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.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
  18. 18.🔦 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
  19. 19.🔦 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
  20. 20.🔁 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
  21. 21.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) a wire is cut
  22. 22.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
  23. 23.🔦 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
  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. A gap in one wire is bridged by a copper wire. Does the bulb glow? (a) Yes (b) No
  25. 25.🔦 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) No (b) Yes
  26. 26.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  27. 27.🔦 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
  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. Does the bulb glow? (a) Yes (b) No
  29. 29.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) the switch is OFF
  30. 30.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
  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 rubber eraser. 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 steel coin. Does the bulb glow? (a) Yes (b) No
  33. 33.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
  34. 34.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  35. 35.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  36. 36.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
  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 graphite rod. Does the bulb glow? (a) Yes (b) No
  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. A gap in one wire is bridged by a steel coin. Does the bulb glow? (a) No (b) Yes
  39. 39.🔦 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
  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 plastic straw. Does the bulb glow? (a) Yes (b) No

Answer key

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

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