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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 369 · 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) the loop is complete (c) the switch is ON (d) all wires are joined
  2. 2.🔦 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 woollen thread. Does the bulb glow? (a) Yes (b) No
  3. 3.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
  4. 4.Which of these means the circuit is open? (a) a wire is cut (b) all wires are joined (c) the loop is complete (d) the switch is ON
  5. 5.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  6. 6.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  7. 7.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the filament (d) the switch
  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 a plastic straw. Does the bulb glow? (a) No (b) Yes
  10. 10.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  11. 11.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a full circuit (c) a series circuit (d) a closed circuit
  12. 12.Which of these means the circuit is closed? (a) a wire has come loose (b) the bulb is unscrewed (c) the loop is complete (d) a wire is cut
  13. 13.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is ON (c) a cell is taken out (d) the bulb is unscrewed
  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. Does the bulb glow? (a) No (b) Yes
  15. 15.🔦 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 rubber eraser. Does the bulb glow? (a) No (b) Yes
  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 ceramic cup. Does the bulb glow? (a) Yes (b) No
  17. 17.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) both of them (c) it does not matter (d) only one
  18. 18.🔦 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) Yes (b) No
  19. 19.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
  20. 20.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  21. 21.🔁 What must there be for a current to flow? (a) a complete loop (b) one loose end (c) a broken path (d) a plastic gap
  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 brass key. Does the bulb glow? (a) No (b) Yes
  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 copper wire. Does the bulb glow? (a) No (b) Yes
  24. 24.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
  25. 25.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  26. 26.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) the bulb is unscrewed (d) all wires are joined
  27. 27.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
  28. 28.🔦 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
  29. 29.🔦 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) Yes (b) No
  30. 30.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  31. 31.Which of these means the circuit is open? (a) the switch is ON (b) the switch is OFF (c) all wires are joined (d) the loop is complete
  32. 32.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 has come loose
  33. 33.🔦 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) No (b) Yes
  34. 34.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
  35. 35.Which of these means the circuit is closed? (a) all wires are joined (b) a cell is taken out (c) the switch is OFF (d) the bulb is unscrewed
  36. 36.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  37. 37.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
  38. 38.🔦 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 copper wire. Does the bulb glow? (a) Yes (b) No
  39. 39.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  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 steel coin. Does the bulb glow? (a) Yes (b) No

Answer key

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

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