Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 655 · 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.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
2. 2.🔦 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 eraser. Does the bulb glow? (a) No (b) Yes
3. 3.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the base (d) the switch
4. 4.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No
5. 5.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
6. 6.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a closed circuit (c) a series circuit (d) an open circuit
7. 7.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is ON (c) the bulb is unscrewed (d) the switch is OFF
8. 8.🔦 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
9. 9.🔦 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
10. 10.🔁 What must there be for a current to flow? (a) a plastic gap (b) a broken path (c) one loose end (d) a complete loop
11. 11.Which of these means the circuit is open? (a) the switch is ON (b) a wire has come loose (c) the loop is complete (d) all wires are joined
12. 12.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
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 aluminium foil. Does the bulb glow? (a) Yes (b) No
14. 14.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
15. 15.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
16. 16.🔦 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 aluminium foil. Does the bulb glow? (a) Yes (b) No
17. 17.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
18. 18.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) none (c) only one (d) it does not matter
19. 19.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the switch is ON (c) the loop is complete (d) all wires are joined
20. 20.🔦 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) No (b) Yes
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 copper wire. Does the bulb glow? (a) Yes (b) No
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 steel spoon. Does the bulb glow? (a) Yes (b) No
23. 23.Which of these means the circuit is open? (a) the loop is complete (b) a wire is cut (c) the switch is ON (d) all wires are joined
24. 24.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
25. 25.🔦 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
26. 26.🔦 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
27. 27.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
28. 28.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
29. 29.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
30. 30.Which of these means the circuit is closed? (a) the loop is complete (b) a cell is taken out (c) the switch is OFF (d) a wire is cut
31. 31.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
32. 32.🔦 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) 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.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
35. 35.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
36. 36.🔦 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
37. 37.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
38. 38.🔦 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 steel coin. Does the bulb glow? (a) Yes (b) No
39. 39.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
40. 40.Which of these means the circuit is open? (a) the loop is complete (b) a cell is taken out (c) the switch is ON (d) all wires are joined

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