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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 134 · 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 has come loose (b) the bulb is unscrewed (c) a wire is cut (d) the switch is ON
  2. 2.🔦 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
  3. 3.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) it does not matter (c) both of them (d) only one
  4. 4.🔦 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) No (b) Yes
  5. 5.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
  6. 6.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
  7. 7.🔁 Is the circuit closed or open if the switch is ON? (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) Yes (b) No
  9. 9.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
  10. 10.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  11. 11.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
  12. 12.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the switch (d) the filament
  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 glass marble. Does the bulb glow? (a) No (b) Yes
  14. 14.🔦 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 copper wire. Does the bulb glow? (a) Yes (b) No
  15. 15.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a series circuit (c) an open circuit (d) a full circuit
  16. 16.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire has come loose (c) a cell is taken out (d) all wires are joined
  17. 17.🔦 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) No (b) Yes
  18. 18.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  19. 19.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a complete loop (d) a broken path
  20. 20.🔦 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
  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) No (b) Yes
  22. 22.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
  23. 23.🔦 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) No (b) Yes
  24. 24.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) the switch is OFF
  25. 25.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  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 copper wire. Does the bulb glow? (a) Yes (b) No
  27. 27.🔦 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 rubber band. Does the bulb glow? (a) No (b) Yes
  28. 28.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
  29. 29.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
  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) Yes (b) No
  31. 31.🔦 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
  32. 32.🔦 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 brass key. Does the bulb glow? (a) No (b) Yes
  33. 33.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
  34. 34.Which of these means the circuit is open? (a) all wires are joined (b) a cell is taken out (c) the loop is complete (d) the switch is ON
  35. 35.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
  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. A gap in one wire is bridged by a steel coin. 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 brass key. Does the bulb glow? (a) Yes (b) No
  38. 38.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
  39. 39.🔦 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
  40. 40.Which of these means the circuit is closed? (a) a wire is cut (b) the loop is complete (c) the bulb is unscrewed (d) the switch is OFF

Answer key

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

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