Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 512 · 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.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
3. 3.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
4. 4.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
5. 5.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a plastic gap (d) a complete loop
6. 6.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
7. 7.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
8. 8.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) none (d) both of them
9. 9.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
10. 10.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
11. 11.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
12. 12.🔦 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
13. 13.🔦 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
14. 14.Which of these means the circuit is closed? (a) the switch is ON (b) a cell is taken out (c) a wire has come loose (d) a wire is cut
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 plastic ruler. Does the bulb glow? (a) Yes (b) No
16. 16.🔁 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
17. 17.🔦 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
18. 18.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
19. 19.🔦 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
20. 20.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
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 steel coin. Does the bulb glow? (a) Yes (b) No
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. A gap in one wire is bridged by a rubber eraser. Does the bulb glow? (a) No (b) Yes
23. 23.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
24. 24.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) all wires are joined (c) the switch is OFF (d) a wire has come loose
25. 25.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
26. 26.Which of these means the circuit is closed? (a) the loop is complete (b) a wire is cut (c) a wire has come loose (d) the bulb is unscrewed
27. 27.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
28. 28.🔦 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
29. 29.🔦 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
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. A gap in one wire is bridged by a glass marble. Does the bulb glow? (a) Yes (b) No
31. 31.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
32. 32.Which of these means the circuit is open? (a) the loop is complete (b) a wire is cut (c) all wires are joined (d) the switch is ON
33. 33.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
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 plastic ruler. Does the bulb glow? (a) Yes (b) No
35. 35.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
36. 36.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the base (d) the glass
37. 37.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
38. 38.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) the switch is OFF
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 eraser. Does the bulb glow? (a) No (b) Yes
40. 40.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False

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