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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 781 · 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 ON. One wire has come loose from the cell. Does the bulb glow? (a) Yes (b) No
  2. 2.🔁 Is the circuit closed or open if a wire has come loose? (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 aluminium foil. Does the bulb glow? (a) Yes (b) No
  4. 4.Which of these means the circuit is closed? (a) a wire is cut (b) the bulb is unscrewed (c) a wire has come loose (d) the loop is complete
  5. 5.🔦 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
  6. 6.Which of these means the circuit is open? (a) the loop is complete (b) a wire is cut (c) all wires are joined (d) the switch is ON
  7. 7.🔦 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
  8. 8.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) both of them (d) none
  9. 9.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
  10. 10.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the glass (d) the switch
  11. 11.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  12. 12.🔦 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
  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 steel spoon. Does the bulb glow? (a) No (b) Yes
  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 copper wire. 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.🔁 What must there be for a current to flow? (a) a plastic gap (b) a broken path (c) one loose end (d) a complete loop
  17. 17.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  18. 18.🔦 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) No (b) Yes
  19. 19.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a wire has come loose
  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 plastic straw. Does the bulb glow? (a) No (b) Yes
  21. 21.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
  22. 22.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  23. 23.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  24. 24.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  25. 25.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) a series circuit (d) an open circuit
  26. 26.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  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 eraser. Does the bulb glow? (a) Yes (b) No
  28. 28.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
  29. 29.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
  30. 30.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
  31. 31.🔦 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
  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. Does the bulb glow? (a) Yes (b) No
  33. 33.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
  34. 34.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
  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 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
  37. 37.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
  38. 38.🔦 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 ceramic cup. Does the bulb glow? (a) Yes (b) No
  39. 39.🔦 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) No (b) Yes
  40. 40.🔦 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) No (b) Yes

Answer key

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

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