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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 384 · 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 switch is OFF (c) the loop is complete (d) the bulb is unscrewed
  2. 2.🔦 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
  3. 3.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is ON (c) a wire has come loose (d) the switch is OFF
  4. 4.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
  5. 5.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
  6. 6.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a series circuit (c) a full circuit (d) a closed circuit
  7. 7.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
  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 a brass key. Does the bulb glow? (a) Yes (b) No
  9. 9.🔁 What must there be for a current to flow? (a) a plastic gap (b) a complete loop (c) one loose end (d) a broken path
  10. 10.🔁 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
  11. 11.🔦 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
  12. 12.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
  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 ceramic cup. Does the bulb glow? (a) Yes (b) No
  14. 14.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) the bulb is unscrewed (d) all wires are joined
  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 wooden stick. Does the bulb glow? (a) Yes (b) No
  16. 16.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  17. 17.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
  18. 18.🔦 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
  19. 19.Which of these means the circuit is open? (a) the loop is complete (b) a wire has come loose (c) the switch is ON (d) all wires are joined
  20. 20.Which of these means the circuit is closed? (a) a wire has come loose (b) the bulb is unscrewed (c) all wires are joined (d) a cell is taken out
  21. 21.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
  22. 22.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  23. 23.🔦 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) Yes (b) No
  24. 24.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the filament (c) the base (d) the glass
  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 glass marble. Does the bulb glow? (a) Yes (b) No
  26. 26.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
  27. 27.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
  28. 28.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  29. 29.🔦 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 plastic straw. Does the bulb glow? (a) Yes (b) No
  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. 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 an iron nail. Does the bulb glow? (a) Yes (b) No
  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 plastic ruler. Does the bulb glow? (a) No (b) Yes
  33. 33.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
  34. 34.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
  35. 35.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
  36. 36.Which of these means the circuit is open? (a) the switch is ON (b) a wire is cut (c) all wires are joined (d) the loop is complete
  37. 37.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  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 aluminium foil. Does the bulb glow? (a) Yes (b) No
  39. 39.🔦 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
  40. 40.🔦 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 aluminium foil. Does the bulb glow? (a) Yes (b) No

Answer key

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

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