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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 647 · 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.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  2. 2.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) none (c) only one (d) it does not matter
  3. 3.🔦 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
  4. 4.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the filament (c) the glass (d) the base
  5. 5.Which of these means the circuit is open? (a) all wires are joined (b) a cell is taken out (c) the switch is ON (d) the loop is complete
  6. 6.🔦 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
  7. 7.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  8. 8.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  9. 9.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
  10. 10.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire has come loose (c) all wires are joined (d) a wire is cut
  11. 11.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
  12. 12.🔦 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) Yes (b) No
  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. A gap in one wire is bridged by a ceramic cup. Does the bulb glow? (a) No (b) Yes
  14. 14.🔦 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) 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 copper wire. Does the bulb glow? (a) No (b) Yes
  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 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) No (b) Yes
  18. 18.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
  19. 19.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  20. 20.🔁 What must there be for a current to flow? (a) a plastic gap (b) a broken path (c) one loose end (d) a complete loop
  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 paper strip. Does the bulb glow? (a) Yes (b) No
  22. 22.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  23. 23.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
  24. 24.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
  25. 25.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) the bulb is unscrewed
  26. 26.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
  27. 27.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  28. 28.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  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 brass key. Does the bulb glow? (a) No (b) Yes
  30. 30.🔦 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
  31. 31.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
  32. 32.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
  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 a steel spoon. Does the bulb glow? (a) No (b) Yes
  34. 34.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) a wire has come loose
  35. 35.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  36. 36.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a wire is cut (d) all wires are joined
  37. 37.🔦 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
  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 graphite rod. Does the bulb glow? (a) No (b) Yes
  39. 39.🔦 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 rubber eraser. Does the bulb glow? (a) Yes (b) No
  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. closed
  2. both of them
  3. Yes
  4. the filament
  5. a cell is taken out
  6. Yes
  7. closed
  8. open
  9. False
  10. all wires are joined
  11. True
  12. No
  13. No
  14. No
  15. No
  16. No
  17. No
  18. True
  19. open
  20. a complete loop
  21. No
  22. open
  23. False
  24. False
  25. the bulb is unscrewed
  26. False
  27. closed
  28. open
  29. Yes
  30. No
  31. True
  32. True
  33. Yes
  34. a wire has come loose
  35. open
  36. a wire is cut
  37. Yes
  38. No
  39. No
  40. No

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