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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 926 · 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.🔦 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
  2. 2.Which of these means the circuit is closed? (a) all wires are joined (b) the bulb is unscrewed (c) a wire is cut (d) the switch is OFF
  3. 3.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) only one (c) both of them (d) none
  4. 4.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  5. 5.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) a complete loop (d) one loose end
  6. 6.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  7. 7.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is ON (c) a wire has come loose (d) the bulb is unscrewed
  8. 8.🔦 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 plastic straw. Does the bulb glow? (a) No (b) Yes
  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 plastic straw. Does the bulb glow? (a) No (b) Yes
  10. 10.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
  11. 11.🔦 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 spoon. Does the bulb glow? (a) No (b) Yes
  12. 12.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  13. 13.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
  14. 14.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  15. 15.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) a cell is taken out (d) all wires are joined
  16. 16.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
  17. 17.🔦 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 glass marble. Does the bulb glow? (a) No (b) Yes
  18. 18.Which of these means the circuit is open? (a) the switch is ON (b) the bulb is unscrewed (c) the loop is complete (d) all wires are joined
  19. 19.🔦 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
  20. 20.🔦 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
  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) No (b) Yes
  22. 22.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
  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 dry cork. Does the bulb glow? (a) Yes (b) No
  24. 24.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 wire has come loose
  25. 25.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
  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) the switch is OFF
  27. 27.Which of these means the circuit is closed? (a) the loop is complete (b) a wire is cut (c) a wire has come loose (d) the switch is OFF
  28. 28.🔦 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 cotton thread. Does the bulb glow? (a) No (b) Yes
  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 steel spoon. 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. One wire has come loose from the cell. A gap in one wire is bridged by a rubber eraser. Does the bulb glow? (a) Yes (b) No
  31. 31.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  32. 32.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the filament (d) the switch
  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 ceramic cup. Does the bulb glow? (a) No (b) Yes
  34. 34.🔦 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
  35. 35.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
  36. 36.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  37. 37.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
  38. 38.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) a wire is cut (d) the switch is ON
  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 a glass marble. 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 brass key. Does the bulb glow? (a) No (b) Yes

Answer key

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

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