Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 64 · 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) the switch is OFF (b) a cell is taken out (c) the bulb is unscrewed (d) all wires are joined
2. 2.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
3. 3.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
4. 4.🔦 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 steel spoon. Does the bulb glow? (a) Yes (b) No
5. 5.🔦 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
6. 6.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
7. 7.True or false: if the loop is complete, 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) it does not matter (b) only one (c) none (d) both of them
9. 9.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the base (d) the switch
10. 10.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a plastic gap (d) a broken path
11. 11.🔦 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
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.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire is cut (c) a cell is taken out (d) the loop is complete
14. 14.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
15. 15.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
16. 16.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) an open circuit (c) a full circuit (d) a closed circuit
17. 17.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
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 cotton thread. 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 a safety pin. Does the bulb glow? (a) No (b) Yes
20. 20.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
21. 21.🔦 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
22. 22.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
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 metal paper clip. Does the bulb glow? (a) Yes (b) No
24. 24.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
25. 25.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
26. 26.🔦 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) Yes (b) No
27. 27.🔦 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 band. Does the bulb glow? (a) Yes (b) No
28. 28.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
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 graphite rod. Does the bulb glow? (a) No (b) Yes
30. 30.Which of these means the circuit is open? (a) all wires are joined (b) a cell is taken out (c) the loop is complete (d) the switch is ON
31. 31.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
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 rubber band. 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.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) a wire is cut (d) the switch is ON
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 aluminium foil. Does the bulb glow? (a) Yes (b) No
36. 36.🔦 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
37. 37.Which of these means the circuit is open? (a) a wire has come loose (b) the switch is ON (c) all wires are joined (d) the loop is complete
38. 38.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
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) Yes (b) No
40. 40.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True

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