Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 868 · 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 aluminium foil. Does the bulb glow? (a) Yes (b) No
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 paper strip. Does the bulb glow? (a) Yes (b) No
3. 3.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
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. Does the bulb glow? (a) No (b) Yes
5. 5.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
6. 6.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) all wires are joined (c) a wire has come loose (d) the switch is OFF
7. 7.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No
8. 8.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
9. 9.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
10. 10.🔦 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
11. 11.🔦 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
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 graphite rod. Does the bulb glow? (a) No (b) Yes
13. 13.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
14. 14.Which of these means the circuit is closed? (a) a cell is taken out (b) the bulb is unscrewed (c) the loop is complete (d) a wire is cut
15. 15.🔦 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 glass marble. Does the bulb glow? (a) No (b) Yes
16. 16.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
17. 17.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
18. 18.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
19. 19.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
20. 20.🔦 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) Yes (b) No
21. 21.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) only one (c) both of them (d) none
22. 22.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a cell is taken out (c) the switch is ON (d) the switch is OFF
23. 23.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) a wire is cut
24. 24.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
25. 25.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
26. 26.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the base (c) the filament (d) the glass
27. 27.🔦 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
28. 28.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
29. 29.Which of these means the circuit is open? (a) all wires are joined (b) a wire has come loose (c) the loop is complete (d) the switch is ON
30. 30.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
31. 31.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) the switch is OFF
32. 32.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
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 glass marble. Does the bulb glow? (a) No (b) Yes
34. 34.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
35. 35.🔦 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
36. 36.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) a plastic gap (d) one loose end
37. 37.🔦 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
38. 38.🔦 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) No (b) Yes
39. 39.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
40. 40.🔦 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

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