Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 725 · 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. 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
2. 2.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) it does not matter (c) only one (d) none
3. 3.🔦 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) No (b) Yes
4. 4.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) an open circuit (d) a series circuit
5. 5.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
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 metal paper clip. Does the bulb glow? (a) No (b) Yes
7. 7.🔦 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) No (b) Yes
8. 8.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
9. 9.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a complete loop (d) a broken path
10. 10.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
11. 11.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
12. 12.Which of these means the circuit is open? (a) a cell is taken out (b) the switch is ON (c) the loop is complete (d) all wires are joined
13. 13.🔦 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) No (b) Yes
14. 14.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
15. 15.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
16. 16.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
17. 17.🔦 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
18. 18.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire is cut (c) a wire has come loose (d) all wires are joined
19. 19.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
20. 20.🔦 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 safety pin. Does the bulb glow? (a) No (b) Yes
21. 21.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the bulb is unscrewed (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 a cotton thread. Does the bulb glow? (a) Yes (b) No
23. 23.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No
24. 24.🔦 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
25. 25.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
26. 26.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
27. 27.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
28. 28.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
29. 29.🔦 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 metal paper clip. Does the bulb glow? (a) Yes (b) No
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 steel coin. Does the bulb glow? (a) Yes (b) No
31. 31.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
32. 32.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
33. 33.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
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 a steel coin. Does the bulb glow? (a) Yes (b) No
35. 35.Which of these means the circuit is open? (a) a wire is cut (b) all wires are joined (c) the switch is ON (d) the loop is complete
36. 36.🔦 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 straw. Does the bulb glow? (a) No (b) Yes
37. 37.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
38. 38.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
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 rubber band. Does the bulb glow? (a) No (b) Yes
40. 40.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No

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