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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 533 · 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) the switch is OFF (b) a wire is cut (c) the loop is complete (d) a cell is taken out
  2. 2.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
  3. 3.🔦 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) Yes (b) No
  4. 4.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the filament (d) the base
  5. 5.Which of these means the circuit is open? (a) all wires are joined (b) a wire is cut (c) the switch is ON (d) the loop is complete
  6. 6.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
  7. 7.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
  8. 8.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) an open circuit (d) a series circuit
  9. 9.🔦 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 steel coin. Does the bulb glow? (a) Yes (b) No
  10. 10.🔦 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 glass marble. Does the bulb glow? (a) Yes (b) No
  11. 11.🔦 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
  12. 12.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) none (c) it does not matter (d) both of them
  13. 13.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
  14. 14.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
  15. 15.🔦 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
  16. 16.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  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 wooden stick. Does the bulb glow? (a) Yes (b) No
  18. 18.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  19. 19.🔦 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 ruler. Does the bulb glow? (a) No (b) Yes
  20. 20.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  21. 21.🔦 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 steel coin. Does the bulb glow? (a) No (b) Yes
  22. 22.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
  23. 23.Which of these means the circuit is closed? (a) the switch is ON (b) a wire is cut (c) a cell is taken out (d) a wire has come loose
  24. 24.Which of these means the circuit is closed? (a) a wire is cut (b) a cell is taken out (c) the bulb is unscrewed (d) all wires are joined
  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 plastic straw. Does the bulb glow? (a) Yes (b) No
  26. 26.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a cell is taken out
  27. 27.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a broken path (d) a plastic gap
  28. 28.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
  29. 29.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  30. 30.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
  31. 31.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  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 graphite rod. Does the bulb glow? (a) No (b) Yes
  33. 33.🔦 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
  34. 34.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
  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 steel spoon. Does the bulb glow? (a) Yes (b) No
  36. 36.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
  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 paper strip. Does the bulb glow? (a) No (b) Yes
  38. 38.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
  39. 39.🔦 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 plastic straw. Does the bulb glow? (a) No (b) Yes
  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 rubber eraser. Does the bulb glow? (a) Yes (b) No

Answer key

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

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