Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 100 · 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. One wire has come loose from the cell. Does the bulb glow? (a) No (b) Yes
2. 2.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the switch is ON (c) all wires are joined (d) the loop is complete
3. 3.🔦 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
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.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
6. 6.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
7. 7.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) none (c) only one (d) both of them
8. 8.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a wire is cut (d) all wires are joined
9. 9.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
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 ceramic cup. Does the bulb glow? (a) No (b) Yes
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 a rubber eraser. Does the bulb glow? (a) Yes (b) No
12. 12.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
13. 13.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
14. 14.🔦 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) No (b) Yes
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 woollen thread. Does the bulb glow? (a) No (b) Yes
16. 16.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
17. 17.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
18. 18.🔦 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
19. 19.🔁 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
20. 20.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the switch (d) the base
21. 21.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
22. 22.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is OFF (c) a cell is taken out (d) the switch is ON
23. 23.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a series circuit (c) a closed circuit (d) a full circuit
24. 24.🔦 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
25. 25.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
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 steel spoon. Does the bulb glow? (a) No (b) Yes
27. 27.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
28. 28.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
29. 29.🔦 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
30. 30.🔦 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 plastic straw. Does the bulb glow? (a) No (b) Yes
31. 31.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
32. 32.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is OFF (c) all wires are joined (d) a wire has come loose
33. 33.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a cell is taken out (d) the switch is ON
34. 34.🔦 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
35. 35.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
36. 36.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
37. 37.🔦 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
38. 38.🔦 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) Yes (b) No
39. 39.🔦 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) Yes (b) No
40. 40.🔦 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

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