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Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 646 · 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) the switch is OFF (b) a wire is cut (c) the bulb is unscrewed (d) all wires are joined
  2. 2.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
  3. 3.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the base (d) the switch
  4. 4.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is OFF (c) the switch is ON (d) a wire has come loose
  5. 5.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
  6. 6.🔦 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) Yes (b) No
  7. 7.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
  8. 8.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a cell is taken out (d) all wires are joined
  9. 9.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) only one (c) none (d) it does not matter
  10. 10.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a full circuit (c) an open circuit (d) a closed circuit
  11. 11.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
  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 plastic ruler. Does the bulb glow? (a) No (b) Yes
  13. 13.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
  14. 14.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
  15. 15.🔦 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
  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 copper wire. Does the bulb glow? (a) Yes (b) No
  17. 17.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
  18. 18.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
  19. 19.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
  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. Does the bulb glow? (a) No (b) Yes
  21. 21.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
  22. 22.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
  23. 23.Which of these means the circuit is open? (a) a wire is cut (b) the switch is ON (c) all wires are joined (d) the loop is complete
  24. 24.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
  25. 25.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
  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 a plastic ruler. Does the bulb glow? (a) Yes (b) No
  27. 27.🔦 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
  28. 28.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
  29. 29.🔁 What must there be for a current to flow? (a) a plastic gap (b) a broken path (c) a complete loop (d) one loose end
  30. 30.🔦 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 glass marble. Does the bulb glow? (a) No (b) Yes
  31. 31.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  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 cotton thread. Does the bulb glow? (a) No (b) Yes
  33. 33.🔦 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
  34. 34.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
  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 graphite rod. Does the bulb glow? (a) Yes (b) No
  36. 36.Which of these means the circuit is open? (a) the loop is complete (b) the switch is OFF (c) the switch is ON (d) all wires are joined
  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 a wooden stick. Does the bulb glow? (a) Yes (b) No
  38. 38.🔦 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 aluminium foil. Does the bulb glow? (a) Yes (b) No
  39. 39.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
  40. 40.🔦 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

Answer key

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

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