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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 211 · 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.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the switch (c) the filament (d) the glass
  2. 2.Which of these means the circuit is open? (a) a wire is cut (b) the loop is complete (c) the switch is ON (d) all wires are joined
  3. 3.🔁 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) both of them (d) only one
  4. 4.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
  5. 5.🔦 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 paper strip. Does the bulb glow? (a) No (b) Yes
  6. 6.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  7. 7.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  8. 8.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  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) Yes (b) No
  10. 10.🔦 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
  11. 11.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
  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 safety pin. Does the bulb glow? (a) Yes (b) No
  13. 13.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  14. 14.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the switch is ON (c) the loop is complete (d) all wires are joined
  15. 15.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  16. 16.🔦 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
  17. 17.🔦 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 cotton thread. Does the bulb glow? (a) No (b) Yes
  18. 18.🔦 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
  19. 19.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is OFF (c) a wire is cut (d) all wires are joined
  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 aluminium foil. Does the bulb glow? (a) Yes (b) No
  21. 21.🔁 What must there be for a current to flow? (a) a complete loop (b) a broken path (c) a plastic gap (d) one loose end
  22. 22.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a wire has come loose (d) the switch is ON
  23. 23.🔦 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
  24. 24.🔦 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
  25. 25.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
  26. 26.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
  27. 27.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  28. 28.🔦 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) No (b) Yes
  29. 29.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a closed circuit (c) a full circuit (d) an open circuit
  30. 30.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire is cut (c) the switch is ON (d) the bulb is unscrewed
  31. 31.🔦 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 band. Does the bulb glow? (a) No (b) Yes
  32. 32.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire has come loose (c) the loop is complete (d) a wire is cut
  33. 33.🔦 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
  34. 34.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
  35. 35.True or false: if a wire has come loose, 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. All the wires are firmly joined. A gap in one wire is bridged by aluminium foil. Does the bulb glow? (a) Yes (b) No
  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 ceramic cup. Does the bulb glow? (a) Yes (b) No
  38. 38.Which of these means the circuit is open? (a) the switch is ON (b) the switch is OFF (c) all wires are joined (d) the loop is complete
  39. 39.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
  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 wooden stick. Does the bulb glow? (a) No (b) Yes

Answer key

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

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