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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 948 · 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.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a full circuit (c) a closed circuit (d) a series circuit
  2. 2.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) both of them (c) only one (d) it does not matter
  3. 3.🔦 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
  4. 4.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
  5. 5.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  6. 6.Which of these means the circuit is closed? (a) the switch is ON (b) a cell is taken out (c) the bulb is unscrewed (d) a wire is cut
  7. 7.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  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 an iron nail. Does the bulb glow? (a) Yes (b) No
  9. 9.🔦 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
  10. 10.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  11. 11.🔦 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 ceramic cup. Does the bulb glow? (a) Yes (b) No
  12. 12.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is OFF (c) all wires are joined (d) a cell is taken out
  13. 13.🔦 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) Yes (b) No
  14. 14.True or false: if all wires are joined, 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 safety pin. Does the bulb glow? (a) No (b) Yes
  16. 16.🔁 What must there be for a current to flow? (a) a complete loop (b) a plastic gap (c) a broken path (d) one loose end
  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 metal paper clip. Does the bulb glow? (a) No (b) Yes
  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 graphite rod. Does the bulb glow? (a) Yes (b) No
  19. 19.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
  20. 20.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
  21. 21.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  22. 22.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the glass (d) the base
  23. 23.🔦 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 woollen thread. Does the bulb glow? (a) Yes (b) No
  24. 24.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
  25. 25.🔦 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
  26. 26.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire has come loose (c) the loop is complete (d) the switch is OFF
  27. 27.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  28. 28.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No
  29. 29.🔦 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
  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 ceramic cup. Does the bulb glow? (a) Yes (b) No
  31. 31.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  32. 32.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  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 wooden stick. Does the bulb glow? (a) Yes (b) No
  34. 34.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
  35. 35.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
  36. 36.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
  37. 37.🔦 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
  38. 38.🔦 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) Yes (b) No
  39. 39.Which of these means the circuit is open? (a) a wire has come loose (b) the switch is ON (c) all wires are joined (d) the loop is complete
  40. 40.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True

Answer key

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

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