Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 47 · 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 a cell is taken out? (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.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
4. 4.True or false: if all wires are joined, the circuit is open and no 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 plastic straw. Does the bulb glow? (a) No (b) Yes
6. 6.Which of these means the circuit is closed? (a) a wire is cut (b) a cell is taken out (c) all wires are joined (d) a wire has come loose
7. 7.🔁 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
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 metal paper clip. Does the bulb glow? (a) No (b) Yes
9. 9.Which of these means the circuit is closed? (a) a wire has come loose (b) a wire is cut (c) the switch is ON (d) the bulb is unscrewed
10. 10.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
11. 11.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is OFF (c) a wire is cut (d) the loop is complete
12. 12.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
13. 13.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the filament (d) the switch
14. 14.🔦 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 copper wire. Does the bulb glow? (a) Yes (b) No
15. 15.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
16. 16.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
17. 17.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
18. 18.🔦 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 copper wire. Does the bulb glow? (a) No (b) Yes
19. 19.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
20. 20.🔦 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 steel spoon. Does the bulb glow? (a) Yes (b) No
21. 21.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
22. 22.🔦 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
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 rubber band. Does the bulb glow? (a) Yes (b) No
24. 24.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) both of them (c) only one (d) it does not matter
25. 25.🔦 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) No (b) Yes
26. 26.True or false: if the switch is OFF, 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. Does the bulb glow? (a) Yes (b) No
28. 28.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
29. 29.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
30. 30.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
31. 31.Which of these means the circuit is open? (a) the switch is ON (b) a cell is taken out (c) the loop is complete (d) all wires are joined
32. 32.🔦 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 woollen thread. Does the bulb glow? (a) Yes (b) No
33. 33.🔦 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 paper strip. Does the bulb glow? (a) Yes (b) No
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 safety pin. Does the bulb glow? (a) No (b) Yes
35. 35.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) the switch is OFF
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. Does the bulb glow? (a) Yes (b) No
37. 37.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
38. 38.🔦 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
39. 39.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
40. 40.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed

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