Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 81 · 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.🔦 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
2. 2.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
3. 3.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a broken path (d) a complete loop
4. 4.🔦 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 coin. Does the bulb glow? (a) Yes (b) No
5. 5.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
6. 6.🔦 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 graphite rod. Does the bulb glow? (a) No (b) Yes
7. 7.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
8. 8.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No
9. 9.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is OFF (c) a cell is taken out (d) all wires are joined
10. 10.Which of these means the circuit is closed? (a) a wire is cut (b) the bulb is unscrewed (c) the loop is complete (d) a cell is taken out
11. 11.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) an open circuit (c) a series circuit (d) a full circuit
12. 12.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) it does not matter (c) both of them (d) only one
13. 13.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
14. 14.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
15. 15.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
16. 16.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
17. 17.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
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. Does the bulb glow? (a) No (b) Yes
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 an iron nail. Does the bulb glow? (a) No (b) Yes
20. 20.True or false: if a wire has come loose, the circuit is open and no 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 dry cork. Does the bulb glow? (a) Yes (b) No
22. 22.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
23. 23.🔦 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
24. 24.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
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 metal paper clip. Does the bulb glow? (a) No (b) Yes
26. 26.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
27. 27.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the base (d) the filament
28. 28.Which of these means the circuit is open? (a) the switch is ON (b) a wire is cut (c) all wires are joined (d) the loop is complete
29. 29.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
30. 30.🔦 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
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) Yes (b) No
32. 32.🔦 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 glass marble. Does the bulb glow? (a) No (b) Yes
33. 33.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
34. 34.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
35. 35.🔦 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 ceramic cup. Does the bulb glow? (a) No (b) Yes
36. 36.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
37. 37.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
38. 38.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
39. 39.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) a wire has come loose (d) the switch is ON
40. 40.Which of these means the circuit is open? (a) the bulb is unscrewed (b) all wires are joined (c) the switch is ON (d) the loop is complete

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