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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 18 · 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 bulb is unscrewed (c) the switch is ON (d) a wire has come loose
  2. 2.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  3. 3.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) all wires are joined (c) the switch is OFF (d) a wire is cut
  4. 4.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) none (c) only one (d) both of them
  5. 5.Which of these means the circuit is closed? (a) a wire is cut (b) the loop is complete (c) a cell is taken out (d) the bulb is unscrewed
  6. 6.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
  7. 7.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a full circuit (c) a closed circuit (d) a series circuit
  8. 8.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  9. 9.🔦 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
  10. 10.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
  11. 11.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  12. 12.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
  13. 13.🔦 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
  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 ceramic cup. Does the bulb glow? (a) No (b) Yes
  15. 15.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  16. 16.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) one loose end (d) a complete loop
  17. 17.True or false: if the bulb is unscrewed, 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 OFF. 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
  19. 19.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  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 a graphite rod. Does the bulb glow? (a) No (b) Yes
  21. 21.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
  22. 22.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
  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 ceramic cup. Does the bulb glow? (a) No (b) Yes
  24. 24.🔦 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 metal paper clip. Does the bulb glow? (a) Yes (b) No
  25. 25.🔦 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
  26. 26.🔦 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) Yes (b) No
  27. 27.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
  28. 28.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the glass (c) the switch (d) the filament
  29. 29.🔦 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) Yes (b) No
  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 woollen thread. Does the bulb glow? (a) No (b) Yes
  31. 31.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  32. 32.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the switch is OFF (d) the loop is complete
  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 aluminium foil. Does the bulb glow? (a) No (b) Yes
  34. 34.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
  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 paper strip. Does the bulb glow? (a) Yes (b) No
  36. 36.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
  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 an iron nail. Does the bulb glow? (a) Yes (b) No
  38. 38.🔦 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
  39. 39.🔦 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
  40. 40.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed

Answer key

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

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