Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 598 · 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.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
2. 2.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
3. 3.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
4. 4.🔦 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 dry cork. Does the bulb glow? (a) Yes (b) No
5. 5.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire is cut (c) the bulb is unscrewed (d) all wires are joined
6. 6.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
7. 7.🔦 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
8. 8.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
9. 9.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the base (c) the switch (d) the glass
10. 10.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
11. 11.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is OFF (d) the switch is ON
12. 12.🔦 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
13. 13.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) a wire is cut (d) the loop is complete
14. 14.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) a cell is taken out
15. 15.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
16. 16.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
17. 17.🔦 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) No (b) Yes
18. 18.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
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 steel coin. Does the bulb glow? (a) No (b) Yes
20. 20.🔁 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
21. 21.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
22. 22.🔦 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) Yes (b) No
23. 23.🔦 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
24. 24.🔦 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 paper strip. Does the bulb glow? (a) No (b) Yes
25. 25.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
26. 26.🔦 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
27. 27.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) an open circuit (c) a series circuit (d) a closed circuit
28. 28.🔦 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
29. 29.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is ON (c) the switch is OFF (d) a wire is cut
30. 30.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire has come loose (c) the loop is complete (d) a cell is taken out
31. 31.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
32. 32.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
33. 33.🔁 What must there be for a current to flow? (a) a broken path (b) one loose end (c) a complete loop (d) a plastic gap
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. A gap in one wire is bridged by a cotton thread. Does the bulb glow? (a) No (b) Yes
35. 35.🔦 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
36. 36.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
37. 37.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
38. 38.🔦 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 steel spoon. 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. 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
40. 40.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True

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