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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 457 · 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 closed? (a) a cell is taken out (b) a wire has come loose (c) the switch is ON (d) the switch is OFF
  2. 2.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
  3. 3.🔦 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 metal paper clip. Does the bulb glow? (a) Yes (b) No
  4. 4.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  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 steel spoon. Does the bulb glow? (a) Yes (b) No
  6. 6.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
  7. 7.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
  8. 8.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  9. 9.🔁 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
  10. 10.🔁 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
  11. 11.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  12. 12.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
  13. 13.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  14. 14.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire is cut (c) the loop is complete (d) the bulb is unscrewed
  15. 15.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  16. 16.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
  17. 17.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) an open circuit (c) a series circuit (d) a full circuit
  18. 18.Which of these means the circuit is open? (a) the switch is ON (b) the bulb is unscrewed (c) all wires are joined (d) the loop is complete
  19. 19.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
  20. 20.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
  21. 21.🔦 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) No (b) Yes
  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 brass key. 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.🔦 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
  25. 25.🔦 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) Yes (b) No
  26. 26.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
  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 copper wire. Does the bulb glow? (a) Yes (b) No
  28. 28.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
  29. 29.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
  30. 30.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
  31. 31.Which of these means the circuit is open? (a) all wires are joined (b) a wire is cut (c) the loop is complete (d) the switch is ON
  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 a plastic straw. Does the bulb glow? (a) No (b) Yes
  33. 33.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the switch (d) the base
  34. 34.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) a cell is taken out
  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 copper wire. Does the bulb glow? (a) Yes (b) No
  36. 36.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
  37. 37.🔦 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 dry cork. Does the bulb glow? (a) Yes (b) No
  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 wooden stick. Does the bulb glow? (a) No (b) Yes
  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 an iron nail. Does the bulb glow? (a) Yes (b) No
  40. 40.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False

Answer key

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

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