Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 386 · 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 open? (a) the bulb is unscrewed (b) the loop is complete (c) the switch is ON (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 rubber eraser. Does the bulb glow? (a) No (b) Yes
3. 3.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the switch (d) the base
4. 4.🔦 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) Yes (b) No
5. 5.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) a wire has come loose (d) the switch is ON
6. 6.🔦 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 aluminium foil. Does the bulb glow? (a) Yes (b) No
7. 7.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
8. 8.🔦 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
9. 9.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a cell is taken out (c) all wires are joined (d) the switch is OFF
10. 10.🔦 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 metal paper clip. Does the bulb glow? (a) Yes (b) No
11. 11.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
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. A gap in one wire is bridged by a woollen thread. Does the bulb glow? (a) Yes (b) No
13. 13.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
14. 14.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
15. 15.🔦 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
16. 16.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
17. 17.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) an open circuit (d) a series circuit
18. 18.🔦 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) No (b) Yes
19. 19.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
20. 20.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
21. 21.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
22. 22.🔁 What must there be for a current to flow? (a) a broken path (b) one loose end (c) a plastic gap (d) a complete loop
23. 23.🔦 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 ceramic cup. Does the bulb glow? (a) No (b) Yes
24. 24.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
25. 25.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
26. 26.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
27. 27.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
28. 28.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
29. 29.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
30. 30.Which of these means the circuit is open? (a) the loop is complete (b) a wire is cut (c) the switch is ON (d) all wires are joined
31. 31.🔦 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
32. 32.🔦 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) Yes (b) No
33. 33.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) the loop is complete
34. 34.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
35. 35.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
36. 36.🔦 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 steel spoon. Does the bulb glow? (a) Yes (b) No
37. 37.🔁 Is the circuit closed or open if the switch is OFF? (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.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
40. 40.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes

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