Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 723 · 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 wire is cut (b) the switch is OFF (c) a cell is taken out (d) all wires are joined
2. 2.🔦 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
3. 3.🔦 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 rubber band. Does the bulb glow? (a) No (b) Yes
4. 4.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) a cell is taken out
5. 5.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
6. 6.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
7. 7.🔦 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
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. A gap in one wire is bridged by a plastic straw. Does the bulb glow? (a) No (b) Yes
9. 9.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
10. 10.Which of these means the circuit is closed? (a) a wire is cut (b) the loop is complete (c) a wire has come loose (d) the switch is OFF
11. 11.Which of these means the circuit is open? (a) a wire is cut (b) the loop is complete (c) all wires are joined (d) the switch is ON
12. 12.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
13. 13.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) a complete loop (d) one loose end
14. 14.🔦 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) No (b) Yes
15. 15.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
16. 16.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a series circuit (c) a full circuit (d) an open circuit
17. 17.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
18. 18.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) both of them (c) it does not matter (d) only one
19. 19.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
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 aluminium foil. Does the bulb glow? (a) Yes (b) No
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 rubber band. Does the bulb glow? (a) No (b) Yes
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 copper wire. Does the bulb glow? (a) No (b) Yes
23. 23.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
24. 24.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
25. 25.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
26. 26.🔦 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) Yes (b) No
27. 27.🔦 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) Yes (b) No
28. 28.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
29. 29.🔦 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 paper strip. 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. Does the bulb glow? (a) No (b) Yes
31. 31.🔦 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 eraser. Does the bulb glow? (a) No (b) Yes
32. 32.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
33. 33.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
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 glass marble. 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 paper strip. Does the bulb glow? (a) Yes (b) No
36. 36.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the base (d) the filament
37. 37.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) the bulb is unscrewed
38. 38.🔦 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
39. 39.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
40. 40.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed

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