Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 787 · 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.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
2. 2.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the filament (d) the base
3. 3.Which of these means the circuit is closed? (a) all wires are joined (b) a wire has come loose (c) the bulb is unscrewed (d) a cell is taken out
4. 4.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
5. 5.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire is cut (c) a wire has come loose (d) the switch is ON
6. 6.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) a complete loop (d) one loose end
7. 7.🔦 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
8. 8.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
9. 9.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
10. 10.🔁 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
11. 11.🔦 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
12. 12.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
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. A gap in one wire is bridged by a rubber band. Does the bulb glow? (a) No (b) Yes
14. 14.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
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) No (b) Yes
16. 16.🔦 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 paper strip. Does the bulb glow? (a) Yes (b) No
17. 17.🔦 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
18. 18.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
19. 19.🔦 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
20. 20.Which of these means the circuit is closed? (a) a wire has come loose (b) the bulb is unscrewed (c) the loop is complete (d) a wire is cut
21. 21.🔦 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 straw. Does the bulb glow? (a) Yes (b) No
22. 22.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
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 safety pin. Does the bulb glow? (a) Yes (b) No
24. 24.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
25. 25.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
26. 26.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
27. 27.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
28. 28.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
29. 29.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
30. 30.Which of these means the circuit is open? (a) the loop is complete (b) the switch is OFF (c) all wires are joined (d) the switch is ON
31. 31.🔦 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
32. 32.True or false: if a wire is cut, 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.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
35. 35.Which of these means the circuit is open? (a) all wires are joined (b) a cell is taken out (c) the switch is ON (d) the loop is complete
36. 36.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
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. A gap in one wire is bridged by a plastic straw. 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. 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
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 ceramic cup. Does the bulb glow? (a) No (b) Yes
40. 40.🔦 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 dry cork. Does the bulb glow? (a) No (b) Yes

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