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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 588 · 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.🔦 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
  2. 2.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) one loose end (d) a plastic gap
  3. 3.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  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 ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
  6. 6.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  7. 7.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a wire has come loose (d) all wires are joined
  8. 8.Which of these means the circuit is closed? (a) the loop is complete (b) the switch is OFF (c) a cell is taken out (d) a wire has come loose
  9. 9.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
  10. 10.🔦 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) No (b) Yes
  11. 11.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
  12. 12.🔦 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) No (b) Yes
  13. 13.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) an open circuit (c) a full circuit (d) a closed circuit
  14. 14.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
  15. 15.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
  16. 16.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
  17. 17.Which of these means the circuit is closed? (a) the switch is ON (b) the bulb is unscrewed (c) a wire has come loose (d) a wire is cut
  18. 18.🔦 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
  19. 19.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
  20. 20.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  21. 21.🔦 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
  22. 22.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
  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 plastic ruler. Does the bulb glow? (a) Yes (b) No
  24. 24.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
  25. 25.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  26. 26.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  27. 27.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the switch (d) the base
  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 steel coin. Does the bulb glow? (a) No (b) Yes
  29. 29.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  30. 30.Which of these means the circuit is closed? (a) all wires are joined (b) a cell is taken out (c) a wire has come loose (d) the switch is OFF
  31. 31.🔦 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 spoon. Does the bulb glow? (a) No (b) Yes
  32. 32.Which of these means the circuit is open? (a) all wires are joined (b) the bulb is unscrewed (c) the loop is complete (d) the switch is ON
  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 an iron nail. Does the bulb glow? (a) Yes (b) No
  34. 34.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  35. 35.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
  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 dry cork. Does the bulb glow? (a) Yes (b) No
  37. 37.🔦 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
  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 coin. Does the bulb glow? (a) Yes (b) No
  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 cotton thread. Does the bulb glow? (a) Yes (b) No
  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 a steel coin. Does the bulb glow? (a) Yes (b) No

Answer key

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

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