Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 374 · 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. A gap in one wire is bridged by a cotton thread. Does the bulb glow? (a) Yes (b) No
2. 2.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
3. 3.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a wire has come loose
4. 4.Which of these means the circuit is closed? (a) a wire has come loose (b) the loop is complete (c) a cell is taken out (d) the bulb is unscrewed
5. 5.🔦 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
6. 6.🔦 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 paper strip. Does the bulb glow? (a) No (b) Yes
7. 7.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
8. 8.Which of these means the circuit is open? (a) a cell is taken out (b) all wires are joined (c) the switch is ON (d) the loop is complete
9. 9.🔁 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
10. 10.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) the switch is OFF
11. 11.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
12. 12.🔦 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 coin. Does the bulb glow? (a) No (b) Yes
13. 13.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
14. 14.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
15. 15.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) a wire has come loose
16. 16.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
17. 17.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the bulb is unscrewed (d) the switch is ON
18. 18.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
19. 19.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
20. 20.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
21. 21.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
22. 22.🔁 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
23. 23.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
24. 24.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
25. 25.🔦 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) Yes (b) No
26. 26.🔦 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
27. 27.🔦 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 plastic straw. Does the bulb glow? (a) Yes (b) No
28. 28.Which of these means the circuit is closed? (a) a wire has come loose (b) a cell is taken out (c) the switch is ON (d) a wire is cut
29. 29.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the base (d) the glass
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 glass marble. Does the bulb glow? (a) No (b) Yes
31. 31.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
32. 32.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
33. 33.🔦 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
34. 34.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
35. 35.🔦 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
36. 36.🔦 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
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) Yes (b) No
38. 38.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
39. 39.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
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 an iron nail. Does the bulb glow? (a) Yes (b) No

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