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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 238 · 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 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
  2. 2.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  3. 3.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) the switch is ON
  4. 4.🔦 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
  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 glass marble. Does the bulb glow? (a) No (b) Yes
  6. 6.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
  7. 7.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
  8. 8.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  9. 9.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the filament (d) the base
  10. 10.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a series circuit (c) a closed circuit (d) a full circuit
  11. 11.🔦 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
  12. 12.🔦 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
  13. 13.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  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 aluminium foil. Does the bulb glow? (a) No (b) Yes
  15. 15.🔁 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
  16. 16.🔦 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
  17. 17.🔦 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
  18. 18.🔦 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) Yes (b) No
  19. 19.Which of these means the circuit is open? (a) the loop is complete (b) a wire is cut (c) the switch is ON (d) all wires are joined
  20. 20.🔦 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 plastic ruler. Does the bulb glow? (a) No (b) Yes
  21. 21.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire is cut (c) the loop is complete (d) the bulb is unscrewed
  22. 22.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
  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. A gap in one wire is bridged by a paper strip. Does the bulb glow? (a) No (b) Yes
  24. 24.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
  25. 25.Which of these means the circuit is closed? (a) all wires are joined (b) the switch is OFF (c) a cell is taken out (d) a wire is cut
  26. 26.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  27. 27.🔦 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
  28. 28.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
  29. 29.🔦 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
  30. 30.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) a cell is taken out (d) the loop is complete
  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 safety pin. Does the bulb glow? (a) Yes (b) No
  32. 32.🔦 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
  33. 33.🔦 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
  34. 34.Which of these means the circuit is open? (a) a wire has come loose (b) the switch is ON (c) all wires are joined (d) the loop is complete
  35. 35.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
  36. 36.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
  37. 37.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
  38. 38.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
  39. 39.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the bulb is unscrewed (d) the switch is ON
  40. 40.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False

Answer key

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

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