Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 92 · 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 closed? (a) a cell is taken out (b) a wire is cut (c) the switch is ON (d) the bulb is unscrewed
2. 2.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
3. 3.🔦 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
4. 4.🔦 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
5. 5.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 wire is cut
6. 6.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
7. 7.🔦 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
8. 8.🔦 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
9. 9.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is OFF (c) the loop is complete (d) the bulb is unscrewed
10. 10.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) both of them (c) it does not matter (d) none
11. 11.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
12. 12.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
13. 13.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
14. 14.🔁 What must there be for a current to flow? (a) a plastic gap (b) one loose end (c) a complete loop (d) a broken path
15. 15.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
16. 16.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
17. 17.Which of these means the circuit is closed? (a) a wire is cut (b) all wires are joined (c) a cell is taken out (d) the bulb is unscrewed
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 copper wire. Does the bulb glow? (a) Yes (b) No
19. 19.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
20. 20.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a full circuit (c) an open circuit (d) a closed circuit
21. 21.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) a cell is taken out (d) the loop is complete
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 an iron nail. Does the bulb glow? (a) No (b) Yes
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 brass key. Does the bulb glow? (a) Yes (b) No
24. 24.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
25. 25.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
26. 26.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
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 woollen thread. Does the bulb glow? (a) No (b) Yes
28. 28.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
29. 29.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
30. 30.🔦 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
31. 31.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
32. 32.Which of these means the circuit is open? (a) a wire has come loose (b) all wires are joined (c) the loop is complete (d) the switch is ON
33. 33.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
34. 34.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
35. 35.🔦 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) No (b) Yes
36. 36.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
37. 37.🔦 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
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 steel coin. Does the bulb glow? (a) Yes (b) No
39. 39.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
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 steel spoon. Does the bulb glow? (a) No (b) Yes

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