Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 407 · 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 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 ceramic cup. Does the bulb glow? (a) Yes (b) No
2. 2.Which of these means the circuit is closed? (a) the loop is complete (b) the bulb is unscrewed (c) a cell is taken out (d) a wire is cut
3. 3.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
4. 4.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
5. 5.🔦 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) No (b) Yes
6. 6.🔦 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
7. 7.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
8. 8.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
9. 9.🔦 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
10. 10.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
11. 11.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
12. 12.🔁 What must there be for a current to flow? (a) a broken path (b) one loose end (c) a complete loop (d) a plastic gap
13. 13.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the loop is complete (c) the switch is ON (d) all wires are joined
14. 14.Which of these means the circuit is open? (a) a wire has come loose (b) all wires are joined (c) the switch is ON (d) the loop is complete
15. 15.🔁 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
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 dry cork. Does the bulb glow? (a) Yes (b) No
17. 17.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
18. 18.🔦 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 wooden stick. Does the bulb glow? (a) No (b) Yes
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 cotton thread. Does the bulb glow? (a) Yes (b) No
20. 20.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
21. 21.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is OFF (c) the switch is ON (d) a wire has come loose
22. 22.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
23. 23.🔦 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
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. Does the bulb glow? (a) Yes (b) No
25. 25.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
26. 26.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
27. 27.🔦 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) No (b) Yes
28. 28.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is OFF (c) all wires are joined (d) a wire is cut
29. 29.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a wire is cut (d) all wires are joined
30. 30.🔦 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 cotton thread. Does the bulb glow? (a) No (b) Yes
31. 31.🔦 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) Yes (b) No
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. A gap in one wire is bridged by an iron nail. Does the bulb glow? (a) No (b) Yes
33. 33.Which of these means the circuit is open? (a) the switch is OFF (b) the switch is ON (c) the loop is complete (d) all wires are joined
34. 34.🔦 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
35. 35.🔦 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
36. 36.🔦 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
37. 37.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the switch (d) the base
38. 38.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
39. 39.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
40. 40.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed

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