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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 523 · 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 OFF. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
  2. 2.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) a cell is taken out (d) the loop is complete
  3. 3.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  4. 4.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a complete loop (d) a plastic gap
  5. 5.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  6. 6.🔦 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
  7. 7.Which of these means the circuit is closed? (a) a wire has come loose (b) all wires are joined (c) a cell is taken out (d) the switch is OFF
  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 dry cork. Does the bulb glow? (a) No (b) Yes
  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) Yes (b) No
  10. 10.🔦 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
  11. 11.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  12. 12.Which of these means the circuit is closed? (a) the switch is ON (b) a wire is cut (c) a cell is taken out (d) the switch is OFF
  13. 13.Which of these means the circuit is closed? (a) a wire is cut (b) the loop is complete (c) the switch is OFF (d) the bulb is unscrewed
  14. 14.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  15. 15.🔦 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
  16. 16.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the switch (d) the base
  17. 17.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
  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 safety pin. 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. All the wires are firmly joined. A gap in one wire is bridged by a paper strip. Does the bulb glow? (a) Yes (b) No
  20. 20.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a series circuit (d) a full circuit
  21. 21.🔦 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
  22. 22.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) a wire is cut (d) the loop is complete
  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 brass key. Does the bulb glow? (a) Yes (b) No
  24. 24.🔦 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
  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 cotton thread. Does the bulb glow? (a) No (b) Yes
  26. 26.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  27. 27.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
  28. 28.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
  29. 29.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) only one (c) none (d) it does not matter
  30. 30.🔦 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 rubber band. Does the bulb glow? (a) Yes (b) No
  31. 31.🔦 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) No (b) Yes
  32. 32.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  33. 33.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
  34. 34.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
  35. 35.🔦 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
  36. 36.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
  37. 37.🔦 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) Yes (b) No
  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 wooden stick. Does the bulb glow? (a) No (b) Yes
  39. 39.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the bulb is unscrewed (d) the switch is ON
  40. 40.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) the switch is OFF (d) all wires are joined

Answer key

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

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