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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 283 · 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 closed? (a) a wire is cut (b) the bulb is unscrewed (c) the switch is ON (d) a cell is taken out
  2. 2.🔦 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
  3. 3.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  4. 4.🔦 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
  5. 5.🔦 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
  6. 6.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) the switch is OFF
  7. 7.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
  8. 8.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
  9. 9.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  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 ceramic cup. Does the bulb glow? (a) No (b) Yes
  11. 11.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
  12. 12.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
  13. 13.🔦 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
  14. 14.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  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.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
  17. 17.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the loop is complete (c) all wires are joined (d) the switch is ON
  18. 18.🔦 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
  19. 19.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  20. 20.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
  21. 21.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
  22. 22.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a cell is taken out (d) the switch is ON
  23. 23.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the base (d) the filament
  24. 24.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) only one (c) it does not matter (d) both of them
  25. 25.🔦 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) Yes (b) No
  26. 26.Which of these means the circuit is closed? (a) a wire has come loose (b) all wires are joined (c) a cell is taken out (d) the bulb is unscrewed
  27. 27.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a closed circuit (c) a full circuit (d) an open circuit
  28. 28.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  29. 29.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) the loop is complete (d) a wire has come loose
  30. 30.🔦 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) No (b) Yes
  31. 31.🔦 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
  32. 32.🔦 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 cotton thread. Does the bulb glow? (a) Yes (b) No
  33. 33.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
  34. 34.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
  35. 35.🔦 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
  36. 36.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a complete loop (d) a broken path
  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 wooden stick. 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. 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
  39. 39.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
  40. 40.🔦 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

Answer key

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

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