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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 423 · 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.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
  2. 2.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  3. 3.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a wire is cut
  4. 4.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) only one (c) both of them (d) none
  5. 5.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
  6. 6.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
  7. 7.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the base (c) the filament (d) the glass
  8. 8.🔦 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 steel coin. Does the bulb glow? (a) Yes (b) No
  9. 9.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) the switch is OFF
  10. 10.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
  11. 11.🔁 Is the circuit closed or open if a wire has come loose? (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. Does the bulb glow? (a) No (b) Yes
  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 brass key. Does the bulb glow? (a) No (b) Yes
  14. 14.🔦 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
  15. 15.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  16. 16.🔦 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
  17. 17.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is ON (c) the bulb is unscrewed (d) a wire has come loose
  18. 18.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  19. 19.🔦 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 glass marble. Does the bulb glow? (a) No (b) Yes
  20. 20.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  21. 21.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
  22. 22.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  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. A gap in one wire is bridged by a glass marble. Does the bulb glow? (a) No (b) Yes
  24. 24.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
  25. 25.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  26. 26.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
  27. 27.Which of these means the circuit is open? (a) the switch is ON (b) a cell is taken out (c) all wires are joined (d) the loop is complete
  28. 28.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 bulb is unscrewed
  29. 29.🔦 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
  30. 30.🔦 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
  31. 31.Which of these means the circuit is closed? (a) the loop is complete (b) the switch is OFF (c) a wire has come loose (d) a cell is taken out
  32. 32.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
  33. 33.🔦 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
  34. 34.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
  35. 35.🔦 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 metal paper clip. 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. One wire has come loose from the cell. Does the bulb glow? (a) Yes (b) No
  37. 37.🔦 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 aluminium foil. 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. Does the bulb glow? (a) Yes (b) No
  39. 39.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a series circuit (c) an open circuit (d) a full circuit
  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 plastic straw. Does the bulb glow? (a) Yes (b) No

Answer key

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

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