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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 259 · 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 switch is ON (b) all wires are joined (c) the loop is complete (d) the switch is OFF
  2. 2.Which of these means the circuit is closed? (a) a cell is taken out (b) the loop is complete (c) a wire has come loose (d) a wire is cut
  3. 3.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
  4. 4.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) the bulb is unscrewed
  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.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
  7. 7.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
  8. 8.🔦 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
  9. 9.🔦 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
  10. 10.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) it does not matter (c) only one (d) none
  11. 11.Which of these means the circuit is closed? (a) a wire is cut (b) a wire has come loose (c) the switch is ON (d) the switch is OFF
  12. 12.Which of these means the circuit is open? (a) a wire has come loose (b) the loop is complete (c) the switch is ON (d) all wires are joined
  13. 13.🔦 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 woollen thread. Does the bulb glow? (a) No (b) Yes
  14. 14.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
  15. 15.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a broken path (d) a complete loop
  16. 16.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) the bulb is unscrewed (d) all wires are joined
  17. 17.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the switch (d) the glass
  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 plastic ruler. Does the bulb glow? (a) Yes (b) No
  19. 19.🔦 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
  20. 20.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
  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 rubber band. Does the bulb glow? (a) No (b) Yes
  22. 22.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
  23. 23.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
  24. 24.🔦 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) No (b) Yes
  25. 25.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a series circuit (d) a full circuit
  26. 26.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  27. 27.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  28. 28.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
  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 graphite rod. 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. 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
  31. 31.🔦 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 cotton thread. Does the bulb glow? (a) No (b) Yes
  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 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 plastic straw. Does the bulb glow? (a) No (b) Yes
  34. 34.🔦 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 glass marble. Does the bulb glow? (a) No (b) Yes
  35. 35.🔦 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) No (b) Yes
  36. 36.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
  37. 37.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
  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 plastic straw. Does the bulb glow? (a) Yes (b) No
  39. 39.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  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 plastic ruler. Does the bulb glow? (a) Yes (b) No

Answer key

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

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