Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 699 · 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 the bulb is unscrewed? (a) open (b) closed
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 steel spoon. Does the bulb glow? (a) Yes (b) No
3. 3.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
4. 4.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the base (c) the glass (d) the filament
5. 5.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
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.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire has come loose (c) the switch is ON (d) the switch is OFF
9. 9.Which of these means the circuit is open? (a) all wires are joined (b) a wire has come loose (c) the switch is ON (d) the loop is complete
10. 10.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) a plastic gap (d) one loose end
11. 11.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
12. 12.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is OFF (c) the bulb is unscrewed (d) all wires are joined
13. 13.🔦 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) Yes (b) No
14. 14.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 bulb is unscrewed
15. 15.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
16. 16.🔦 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
17. 17.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a wire is cut
18. 18.🔦 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
19. 19.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
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.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
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 metal paper clip. Does the bulb glow? (a) Yes (b) No
23. 23.Which of these means the circuit is closed? (a) the loop is complete (b) a cell is taken out (c) the bulb is unscrewed (d) a wire is cut
24. 24.🔁 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
25. 25.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
26. 26.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
27. 27.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
28. 28.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
29. 29.🔦 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 glass marble. Does the bulb glow? (a) No (b) Yes
30. 30.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
31. 31.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
32. 32.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
33. 33.True or false: if all wires are joined, the circuit is open and no 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. Does the bulb glow? (a) Yes (b) No
35. 35.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
36. 36.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
37. 37.🔦 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 cotton thread. Does the bulb glow? (a) Yes (b) No
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.🔦 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
40. 40.🔦 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 woollen thread. Does the bulb glow? (a) No (b) Yes

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