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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 714 · 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.Which of these means the circuit is open? (a) a wire has come loose (b) all wires are joined (c) the loop is complete (d) the switch is ON
  2. 2.🔦 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
  3. 3.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
  4. 4.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
  5. 5.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) none (c) only one (d) both of them
  6. 6.🔦 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
  7. 7.🔦 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 cotton thread. Does the bulb glow? (a) Yes (b) No
  8. 8.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  9. 9.🔦 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 ceramic cup. Does the bulb glow? (a) Yes (b) No
  10. 10.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a complete loop (d) a broken path
  11. 11.🔦 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) Yes (b) No
  12. 12.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
  13. 13.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (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 dry cork. Does the bulb glow? (a) Yes (b) No
  15. 15.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
  16. 16.Which of these means the circuit is closed? (a) a cell is taken out (b) the loop is complete (c) the bulb is unscrewed (d) a wire has come loose
  17. 17.🔦 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) No (b) Yes
  18. 18.🔦 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 spoon. Does the bulb glow? (a) No (b) Yes
  19. 19.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  20. 20.🔦 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) No (b) Yes
  21. 21.Which of these means the circuit is closed? (a) a wire is cut (b) all wires are joined (c) the bulb is unscrewed (d) the switch is OFF
  22. 22.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  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 wooden stick. Does the bulb glow? (a) No (b) Yes
  24. 24.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire has come loose (c) the switch is OFF (d) the switch is ON
  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 rubber eraser. Does the bulb glow? (a) Yes (b) No
  26. 26.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  27. 27.🔦 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
  28. 28.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
  29. 29.🔦 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
  30. 30.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  31. 31.🔦 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) Yes (b) No
  32. 32.🔦 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
  33. 33.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the filament (d) the base
  34. 34.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
  35. 35.🔦 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
  36. 36.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a full circuit (c) a closed circuit (d) an open circuit
  37. 37.🔦 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
  38. 38.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
  39. 39.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
  40. 40.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No

Answer key

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

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