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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 632 · 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.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) none (c) both of them (d) it does not matter
  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.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
  4. 4.Which of these means the circuit is closed? (a) the switch is OFF (b) the switch is ON (c) the bulb is unscrewed (d) a wire is cut
  5. 5.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 is cut
  6. 6.Which of these means the circuit is open? (a) all wires are joined (b) the switch is OFF (c) the switch is ON (d) the loop is complete
  7. 7.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  8. 8.🔦 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
  9. 9.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
  10. 10.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the glass (c) the filament (d) the switch
  11. 11.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
  12. 12.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  13. 13.🔦 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
  14. 14.Which of these means the circuit is open? (a) the switch is ON (b) a cell is taken out (c) the loop is complete (d) all wires are joined
  15. 15.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a wire has come loose (d) all wires are joined
  16. 16.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a cell is taken out (c) all wires are joined (d) a wire is cut
  17. 17.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) the bulb is unscrewed
  18. 18.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
  19. 19.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
  20. 20.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  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 eraser. Does the bulb glow? (a) Yes (b) No
  22. 22.🔦 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 metal paper clip. Does the bulb glow? (a) Yes (b) No
  23. 23.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
  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) Yes (b) No
  25. 25.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) a plastic gap (d) one loose end
  26. 26.🔦 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
  27. 27.🔦 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) Yes (b) No
  28. 28.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 wire is cut
  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 rubber band. Does the bulb glow? (a) No (b) Yes
  30. 30.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  31. 31.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  32. 32.🔦 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
  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 an iron nail. Does the bulb glow? (a) No (b) Yes
  34. 34.🔦 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
  35. 35.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
  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 an iron nail. Does the bulb glow? (a) Yes (b) No
  37. 37.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a closed circuit (c) an open circuit (d) a full circuit
  38. 38.🔦 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 ceramic cup. Does the bulb glow? (a) Yes (b) No
  39. 39.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
  40. 40.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True

Answer key

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

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