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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 582 · 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.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
  2. 2.Which of these means the circuit is closed? (a) a wire has come loose (b) a wire is cut (c) the bulb is unscrewed (d) all wires are joined
  3. 3.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
  4. 4.🔦 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
  5. 5.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  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) Yes (b) No
  7. 7.🔦 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 woollen thread. Does the bulb glow? (a) No (b) Yes
  8. 8.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  9. 9.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  10. 10.🔦 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
  11. 11.Which of these means the circuit is open? (a) the loop is complete (b) a cell is taken out (c) all wires are joined (d) the switch is ON
  12. 12.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
  13. 13.🔦 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
  14. 14.🔁 What must there be for a current to flow? (a) a complete loop (b) a plastic gap (c) one loose end (d) a broken path
  15. 15.🔁 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
  16. 16.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 switch is ON
  17. 17.🔦 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
  18. 18.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  19. 19.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the base (d) the filament
  20. 20.🔦 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 graphite rod. Does the bulb glow? (a) No (b) Yes
  21. 21.Which of these means the circuit is closed? (a) the loop is complete (b) the bulb is unscrewed (c) a wire has come loose (d) the switch is OFF
  22. 22.🔦 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
  23. 23.🔦 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 plastic straw. Does the bulb glow? (a) Yes (b) No
  24. 24.🔦 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) Yes (b) No
  25. 25.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  26. 26.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
  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 rubber eraser. Does the bulb glow? (a) Yes (b) No
  28. 28.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
  29. 29.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
  30. 30.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) the bulb is unscrewed
  31. 31.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
  32. 32.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
  33. 33.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
  34. 34.🔦 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
  35. 35.🔦 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) Yes (b) No
  36. 36.🔦 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
  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 graphite rod. 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. One wire has come loose from the cell. A gap in one wire is bridged by a graphite rod. Does the bulb glow? (a) Yes (b) No
  39. 39.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
  40. 40.🔦 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 safety pin. Does the bulb glow? (a) No (b) Yes

Answer key

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

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