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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 421 · 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.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  3. 3.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
  4. 4.Which of these means the circuit is closed? (a) a cell is taken out (b) the bulb is unscrewed (c) a wire is cut (d) all wires are joined
  5. 5.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
  6. 6.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  7. 7.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the filament (c) the glass (d) the base
  8. 8.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No
  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 woollen thread. Does the bulb glow? (a) No (b) Yes
  10. 10.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  11. 11.Which of these means the circuit is closed? (a) a cell is taken out (b) the bulb is unscrewed (c) the switch is ON (d) a wire has come loose
  12. 12.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the loop is complete (c) the switch is ON (d) all wires are joined
  13. 13.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
  14. 14.🔦 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) Yes (b) No
  15. 15.🔦 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 rubber eraser. Does the bulb glow? (a) Yes (b) No
  16. 16.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
  17. 17.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
  18. 18.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire has come loose (c) the bulb is unscrewed (d) the loop is complete
  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 steel spoon. Does the bulb glow? (a) Yes (b) No
  20. 20.Which of these means the circuit is open? (a) a wire is cut (b) the switch is ON (c) the loop is complete (d) all wires are joined
  21. 21.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
  22. 22.🔦 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
  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 wooden stick. Does the bulb glow? (a) No (b) Yes
  24. 24.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) a cell is taken out
  25. 25.🔁 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
  26. 26.🔦 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
  27. 27.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
  28. 28.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  29. 29.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
  30. 30.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) an open circuit (c) a closed circuit (d) a series circuit
  31. 31.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  32. 32.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
  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) Yes (b) No
  34. 34.🔁 What must there be for a current to flow? (a) a broken path (b) one loose end (c) a plastic gap (d) a complete loop
  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 plastic straw. Does the bulb glow? (a) No (b) Yes
  36. 36.🔦 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
  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 ruler. Does the bulb glow? (a) Yes (b) No
  38. 38.Which of these means the circuit is open? (a) the switch is ON (b) a wire has come loose (c) all wires are joined (d) the loop is complete
  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. A gap in one wire is bridged by a copper wire. Does the bulb glow? (a) Yes (b) No
  40. 40.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True

Answer key

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

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