Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 915 · 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.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
2. 2.Which of these means the circuit is closed? (a) a wire is cut (b) a wire has come loose (c) the switch is OFF (d) the switch is ON
3. 3.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
4. 4.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
5. 5.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
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 plastic straw. Does the bulb glow? (a) Yes (b) No
7. 7.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
8. 8.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) the bulb is unscrewed
9. 9.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
10. 10.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
11. 11.🔦 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
12. 12.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a wire has come loose (d) all wires are joined
13. 13.🔦 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
14. 14.🔦 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
15. 15.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
16. 16.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) the switch is OFF (d) all wires are joined
17. 17.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the glass (d) the base
18. 18.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) an open circuit (c) a full circuit (d) a closed circuit
19. 19.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
20. 20.Which of these means the circuit is closed? (a) the loop is complete (b) a wire has come loose (c) the bulb is unscrewed (d) a cell is taken out
21. 21.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
22. 22.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
23. 23.🔦 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 glass marble. Does the bulb glow? (a) Yes (b) No
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. A gap in one wire is bridged by a brass key. Does the bulb glow? (a) Yes (b) No
25. 25.🔦 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 woollen thread. Does the bulb glow? (a) Yes (b) No
26. 26.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
27. 27.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
28. 28.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) a cell is taken out
29. 29.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
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 glass marble. 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 plastic ruler. 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. 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. One wire has come loose from the cell. A gap in one wire is bridged by a wooden stick. Does the bulb glow? (a) Yes (b) No
34. 34.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
35. 35.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
36. 36.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
37. 37.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
38. 38.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
39. 39.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
40. 40.🔁 What must there be for a current to flow? (a) a plastic gap (b) a complete loop (c) a broken path (d) one loose end

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