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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 629 · 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 closed? (a) the switch is OFF (b) a wire is cut (c) a wire has come loose (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. A gap in one wire is bridged by a cotton thread. Does the bulb glow? (a) No (b) Yes
  3. 3.🔦 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 dry cork. Does the bulb glow? (a) Yes (b) No
  4. 4.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) a cell is taken out
  5. 5.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
  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) No (b) Yes
  7. 7.🔦 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) Yes (b) No
  8. 8.🔦 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 copper wire. Does the bulb glow? (a) No (b) Yes
  9. 9.🔁 What must there be for a current to flow? (a) a plastic gap (b) a broken path (c) one loose end (d) a complete loop
  10. 10.🔦 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
  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 metal paper clip. Does the bulb glow? (a) No (b) Yes
  12. 12.🔦 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
  13. 13.🔦 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
  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 glass marble. Does the bulb glow? (a) No (b) Yes
  15. 15.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
  16. 16.🔦 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) No (b) Yes
  17. 17.🔦 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) No (b) Yes
  18. 18.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
  19. 19.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
  20. 20.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
  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 rubber band. Does the bulb glow? (a) Yes (b) No
  22. 22.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  23. 23.Which of these means the circuit is closed? (a) the loop is complete (b) a wire has come loose (c) the switch is OFF (d) a cell is taken out
  24. 24.🔦 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) No (b) Yes
  25. 25.🔦 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 woollen thread. Does the bulb glow? (a) Yes (b) No
  26. 26.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  27. 27.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 has come loose
  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 spoon. Does the bulb glow? (a) Yes (b) No
  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 copper wire. Does the bulb glow? (a) Yes (b) No
  30. 30.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  31. 31.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
  32. 32.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
  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 a metal paper clip. Does the bulb glow? (a) No (b) Yes
  34. 34.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) none (d) both of them
  35. 35.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  36. 36.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
  37. 37.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  38. 38.🔦 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 ceramic cup. 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
  40. 40.🔁 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

Answer key

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

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