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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 754 · 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 cell is taken out (b) all wires are joined (c) the switch is ON (d) the loop is complete
  2. 2.🔁 What must there be for a current to flow? (a) a plastic gap (b) a complete loop (c) one loose end (d) a broken path
  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 copper wire. Does the bulb glow? (a) No (b) Yes
  4. 4.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) a wire has come loose (d) all wires are joined
  5. 5.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
  6. 6.Which of these means the circuit is closed? (a) a wire is cut (b) the bulb is unscrewed (c) the switch is OFF (d) the loop is complete
  7. 7.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the switch (d) the base
  8. 8.🔦 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) Yes (b) No
  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 an iron nail. Does the bulb glow? (a) Yes (b) No
  10. 10.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) a wire is cut
  11. 11.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is OFF (c) the switch is ON (d) a cell is taken out
  12. 12.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  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 steel coin. Does the bulb glow? (a) No (b) Yes
  14. 14.🔁 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) both of them (d) only one
  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. One wire has come loose from the cell. Does the bulb glow? (a) Yes (b) No
  17. 17.🔦 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
  18. 18.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  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 metal paper clip. Does the bulb glow? (a) Yes (b) No
  20. 20.🔦 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
  21. 21.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  22. 22.🔦 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
  23. 23.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  24. 24.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  25. 25.🔦 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
  26. 26.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
  27. 27.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
  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 cotton thread. Does the bulb glow? (a) No (b) Yes
  29. 29.Which of these means the circuit is open? (a) the loop is complete (b) the bulb is unscrewed (c) the switch is ON (d) all wires are joined
  30. 30.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
  31. 31.🔦 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) No (b) Yes
  32. 32.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  33. 33.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
  34. 34.🔦 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
  35. 35.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the switch is OFF (d) the loop is complete
  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 paper strip. Does the bulb glow? (a) Yes (b) No
  37. 37.🔦 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) Yes (b) No
  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 plastic ruler. Does the bulb glow? (a) Yes (b) No
  39. 39.🔦 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
  40. 40.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a closed circuit (c) a series circuit (d) an open circuit

Answer key

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

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