Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 192 · 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.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
2. 2.🔁 What must there be for a current to flow? (a) a complete loop (b) a broken path (c) a plastic gap (d) one loose end
3. 3.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the glass (d) the switch
4. 4.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
5. 5.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the switch is OFF (d) the loop is complete
6. 6.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) only one (c) it does not matter (d) none
7. 7.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
8. 8.🔦 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
9. 9.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
10. 10.🔦 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 rubber band. Does the bulb glow? (a) No (b) Yes
11. 11.🔦 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
12. 12.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
13. 13.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a series circuit (d) a full circuit
14. 14.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is OFF (c) the loop is complete (d) a wire has come loose
15. 15.🔦 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 woollen thread. Does the bulb glow? (a) Yes (b) No
16. 16.🔦 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
17. 17.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
18. 18.🔦 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 spoon. Does the bulb glow? (a) Yes (b) No
19. 19.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
20. 20.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
21. 21.🔦 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
22. 22.🔦 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 plastic ruler. Does the bulb glow? (a) Yes (b) No
23. 23.🔦 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 dry cork. 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. 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
25. 25.🔦 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) No (b) Yes
26. 26.🔦 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
27. 27.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
28. 28.🔦 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 eraser. Does the bulb glow? (a) Yes (b) No
29. 29.True or false: if a wire has come loose, 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.🔦 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.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) a wire has come loose (d) all wires are joined
33. 33.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
34. 34.🔦 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 cotton thread. Does the bulb glow? (a) Yes (b) No
35. 35.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
36. 36.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is OFF (c) the bulb is unscrewed (d) the switch is ON
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 steel coin. Does the bulb glow? (a) No (b) Yes
38. 38.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
39. 39.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
40. 40.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True

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