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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 683 · 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.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the switch (d) the base
  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 is cut? (a) closed (b) open
  4. 4.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  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) only one (c) both of them (d) none
  6. 6.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) the switch is ON
  7. 7.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
  8. 8.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
  9. 9.🔦 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) Yes (b) No
  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 a plastic ruler. Does the bulb glow? (a) Yes (b) No
  11. 11.🔁 What must there be for a current to flow? (a) a complete loop (b) a broken path (c) one loose end (d) a plastic gap
  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. A gap in one wire is bridged by a metal paper clip. Does the bulb glow? (a) Yes (b) No
  13. 13.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
  14. 14.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  15. 15.🔦 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
  16. 16.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  17. 17.🔦 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 woollen thread. Does the bulb glow? (a) Yes (b) No
  18. 18.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire is cut (c) a wire has come loose (d) the loop is complete
  19. 19.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
  20. 20.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  21. 21.🔦 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) Yes (b) No
  22. 22.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
  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 dry cork. Does the bulb glow? (a) No (b) Yes
  24. 24.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
  25. 25.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
  26. 26.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
  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. A gap in one wire is bridged by a dry cork. Does the bulb glow? (a) No (b) Yes
  28. 28.Which of these means the circuit is open? (a) all wires are joined (b) a wire is cut (c) the loop is complete (d) the switch is ON
  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. Does the bulb glow? (a) Yes (b) No
  30. 30.🔦 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
  31. 31.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  32. 32.Which of these means the circuit is closed? (a) all wires are joined (b) a wire is cut (c) the switch is OFF (d) the bulb is unscrewed
  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 aluminium foil. Does the bulb glow? (a) No (b) Yes
  34. 34.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a series circuit (c) a full circuit (d) a closed circuit
  35. 35.🔦 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 aluminium foil. Does the bulb glow? (a) Yes (b) No
  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. A gap in one wire is bridged by a copper wire. Does the bulb glow? (a) Yes (b) No
  37. 37.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
  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 cotton thread. Does the bulb glow? (a) No (b) Yes
  39. 39.Which of these means the circuit is open? (a) all wires are joined (b) the switch is OFF (c) the loop is complete (d) the switch is ON
  40. 40.🔦 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

Answer key

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

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