Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 703 · 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 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
2. 2.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is OFF (d) the switch is ON
3. 3.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
4. 4.🔦 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
5. 5.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the filament (d) the switch
6. 6.🔦 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
7. 7.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 cell is taken out
8. 8.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire has come loose (c) the loop is complete (d) the switch is OFF
9. 9.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) none (c) it does not matter (d) both of them
10. 10.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
11. 11.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
12. 12.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
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 steel spoon. Does the bulb glow? (a) No (b) Yes
14. 14.Which of these means the circuit is open? (a) the loop is complete (b) a wire is cut (c) all wires are joined (d) the switch is ON
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) Yes (b) No
16. 16.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
17. 17.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
18. 18.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
19. 19.🔦 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 coin. Does the bulb glow? (a) Yes (b) No
20. 20.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
21. 21.🔁 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
22. 22.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire has come loose (c) a wire is cut (d) the switch is ON
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 paper strip. Does the bulb glow? (a) No (b) Yes
24. 24.Which of these means the circuit is open? (a) the bulb is unscrewed (b) all wires are joined (c) the switch is ON (d) the loop is complete
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 safety pin. Does the bulb glow? (a) Yes (b) No
26. 26.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
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 woollen thread. Does the bulb glow? (a) Yes (b) No
28. 28.🔦 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
29. 29.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
30. 30.🔦 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 paper strip. Does the bulb glow? (a) No (b) Yes
31. 31.🔦 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
32. 32.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
33. 33.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
34. 34.🔦 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
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. A gap in one wire is bridged by a metal paper clip. Does the bulb glow? (a) Yes (b) No
36. 36.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
37. 37.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
38. 38.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
39. 39.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
40. 40.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False

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