Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 119 · 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. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
2. 2.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
3. 3.🔦 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
4. 4.🔦 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) Yes (b) No
5. 5.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a complete loop (d) a broken path
6. 6.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) none (c) both of them (d) it does not matter
7. 7.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the switch (d) the filament
8. 8.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
9. 9.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
10. 10.🔦 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 eraser. Does the bulb glow? (a) No (b) Yes
11. 11.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire is cut (c) all wires are joined (d) the bulb is unscrewed
12. 12.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
13. 13.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
14. 14.🔦 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 copper wire. Does the bulb glow? (a) No (b) Yes
15. 15.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) the switch is OFF
16. 16.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
17. 17.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
18. 18.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
19. 19.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
20. 20.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
21. 21.🔦 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 copper wire. Does the bulb glow? (a) Yes (b) No
22. 22.🔦 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
23. 23.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
24. 24.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a series circuit (d) a full circuit
25. 25.🔦 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
26. 26.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
27. 27.Which of these means the circuit is closed? (a) the loop is complete (b) a wire has come loose (c) the switch is OFF (d) the bulb is unscrewed
28. 28.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
29. 29.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) the switch is ON (d) a wire is cut
30. 30.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
31. 31.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
32. 32.🔦 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
33. 33.🔦 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 rubber band. Does the bulb glow? (a) No (b) Yes
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) 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. A gap in one wire is bridged by a paper strip. Does the bulb glow? (a) Yes (b) No
36. 36.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
37. 37.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
38. 38.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
39. 39.🔦 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 plastic ruler. Does the bulb glow? (a) Yes (b) No
40. 40.🔦 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

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