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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 300 · 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.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
  2. 2.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  3. 3.🔦 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
  4. 4.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a full circuit (c) an open circuit (d) a closed circuit
  5. 5.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 cell is taken out
  6. 6.🔁 What must there be for a current to flow? (a) a plastic gap (b) one loose end (c) a broken path (d) a complete loop
  7. 7.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  8. 8.🔦 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
  9. 9.🔁 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
  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 metal paper clip. Does the bulb glow? (a) No (b) Yes
  11. 11.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  12. 12.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is ON (c) the switch is OFF (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. Does the bulb glow? (a) Yes (b) No
  14. 14.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
  15. 15.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
  16. 16.🔦 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) Yes (b) No
  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 copper wire. Does the bulb glow? (a) No (b) Yes
  18. 18.🔦 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 spoon. 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 steel spoon. Does the bulb glow? (a) No (b) Yes
  20. 20.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the switch (d) the glass
  21. 21.🔦 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
  22. 22.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 bulb is unscrewed
  23. 23.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  24. 24.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
  25. 25.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the loop is complete (c) the switch is OFF (d) a wire has come loose
  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 metal paper clip. Does the bulb glow? (a) No (b) Yes
  27. 27.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  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 graphite rod. 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 dry cork. 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 brass key. 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) No (b) Yes
  32. 32.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  33. 33.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
  34. 34.True or false: if a wire has come loose, 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 OFF. All the wires are firmly joined. A gap in one wire is bridged by a dry cork. Does the bulb glow? (a) No (b) Yes
  36. 36.🔦 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) Yes (b) No
  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 plastic straw. Does the bulb glow? (a) No (b) Yes
  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 glass marble. Does the bulb glow? (a) Yes (b) No
  39. 39.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  40. 40.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False

Answer key

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

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