Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 198 · 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.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a series circuit (c) a closed circuit (d) an open circuit
2. 2.🔦 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
3. 3.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
4. 4.🔁 What must there be for a current to flow? (a) a plastic gap (b) a complete loop (c) one loose end (d) a broken path
5. 5.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the glass (d) the switch
6. 6.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 is cut
7. 7.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
8. 8.🔦 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
9. 9.🔦 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
10. 10.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) a wire has come loose (d) the loop is complete
11. 11.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
12. 12.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
13. 13.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
14. 14.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
15. 15.🔦 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) Yes (b) No
16. 16.🔦 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) No (b) Yes
17. 17.Which of these means the circuit is closed? (a) a wire has come loose (b) all wires are joined (c) the switch is OFF (d) a cell is taken out
18. 18.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
19. 19.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
20. 20.🔦 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
21. 21.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
22. 22.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
23. 23.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
24. 24.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
25. 25.🔦 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
26. 26.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
27. 27.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
28. 28.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a wire is cut (d) the switch is ON
29. 29.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
30. 30.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) the switch is OFF
31. 31.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
32. 32.🔦 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) Yes (b) No
33. 33.Which of these means the circuit is open? (a) the loop is complete (b) the bulb is unscrewed (c) all wires are joined (d) the switch is ON
34. 34.🔦 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 steel spoon. Does the bulb glow? (a) Yes (b) No
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 a rubber band. 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.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
38. 38.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
39. 39.🔦 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
40. 40.🔦 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) No (b) Yes

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