Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 954 · 40 questions

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.

1. 1.🔦 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 cotton thread. Does the bulb glow? (a) Yes (b) No
2. 2.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
3. 3.🔦 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
4. 4.🔦 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 aluminium foil. Does the bulb glow? (a) Yes (b) No
5. 5.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) both of them (c) none (d) only one
6. 6.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a complete loop (d) a plastic gap
7. 7.🔦 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 ruler. Does the bulb glow? (a) No (b) Yes
8. 8.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
9. 9.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
10. 10.🔦 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 steel coin. Does the bulb glow? (a) No (b) Yes
11. 11.True or false: if a cell is taken out, the circuit is open and no 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. Does the bulb glow? (a) Yes (b) No
13. 13.🔦 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 dry cork. Does the bulb glow? (a) No (b) Yes
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 a cotton thread. Does the bulb glow? (a) Yes (b) No
15. 15.Which of these means the circuit is closed? (a) the switch is ON (b) the bulb is unscrewed (c) a wire has come loose (d) a cell is taken out
16. 16.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
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 rubber band. 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. A gap in one wire is bridged by a brass key. Does the bulb glow? (a) No (b) Yes
19. 19.Which of these means the circuit is closed? (a) a wire has come loose (b) the bulb is unscrewed (c) the switch is OFF (d) the loop is complete
20. 20.🔦 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
21. 21.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
22. 22.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
23. 23.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
24. 24.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) a wire is cut
25. 25.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
26. 26.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
27. 27.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
28. 28.Which of these means the circuit is closed? (a) all wires are joined (b) the bulb is unscrewed (c) a cell is taken out (d) the switch is OFF
29. 29.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
30. 30.🔦 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
31. 31.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
32. 32.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
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. Does the bulb glow? (a) Yes (b) No
34. 34.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
35. 35.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
36. 36.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
37. 37.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
38. 38.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
39. 39.🔦 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
40. 40.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True

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