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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 756 · 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 open? (a) the loop is complete (b) the switch is ON (c) the switch is OFF (d) all wires are joined
  2. 2.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  3. 3.🔦 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
  4. 4.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  5. 5.🔦 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) Yes (b) No
  6. 6.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) a wire is cut (d) the switch is ON
  7. 7.🔦 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) No (b) Yes
  8. 8.🔦 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
  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 brass key. 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 copper wire. Does the bulb glow? (a) No (b) Yes
  11. 11.🔁 What must there be for a current to flow? (a) a complete loop (b) a plastic gap (c) one loose end (d) a broken path
  12. 12.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
  13. 13.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  14. 14.🔦 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
  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 ceramic cup. Does the bulb glow? (a) No (b) Yes
  16. 16.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a series circuit (c) an open circuit (d) a closed circuit
  17. 17.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the filament (c) the base (d) the glass
  18. 18.🔦 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
  19. 19.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
  20. 20.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
  21. 21.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire has come loose (c) all wires are joined (d) a wire is cut
  22. 22.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  23. 23.Which of these means the circuit is closed? (a) the loop is complete (b) a cell is taken out (c) the bulb is unscrewed (d) a wire is cut
  24. 24.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
  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) only one (c) both of them (d) none
  26. 26.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
  27. 27.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a cell is taken out (c) the switch is OFF (d) the switch is ON
  28. 28.Which of these means the circuit is open? (a) a wire has come loose (b) all wires are joined (c) the loop is complete (d) the switch is ON
  29. 29.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
  30. 30.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
  31. 31.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
  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 aluminium foil. Does the bulb glow? (a) Yes (b) No
  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 steel coin. Does the bulb glow? (a) Yes (b) No
  34. 34.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  35. 35.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a cell is taken out (d) the switch is ON
  36. 36.True or false: if a wire is cut, the circuit is closed and 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
  38. 38.🔦 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 plastic straw. Does the bulb glow? (a) Yes (b) No
  39. 39.🔦 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 spoon. Does the bulb glow? (a) Yes (b) No
  40. 40.🔦 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) Yes (b) No

Answer key

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

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