Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 826 · 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 bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
2. 2.Which of these means the circuit is closed? (a) the loop is complete (b) a wire is cut (c) a wire has come loose (d) a cell is taken out
3. 3.🔁 What must there be for a current to flow? (a) a broken path (b) one loose end (c) a plastic gap (d) a complete loop
4. 4.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
5. 5.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
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 dry cork. Does the bulb glow? (a) Yes (b) No
7. 7.🔦 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
8. 8.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
9. 9.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
10. 10.🔦 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
11. 11.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 wire is cut
12. 12.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
13. 13.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
14. 14.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) both of them (c) it does not matter (d) none
15. 15.Which of these means the circuit is open? (a) the loop is complete (b) the bulb is unscrewed (c) all wires are joined (d) the switch is ON
16. 16.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
17. 17.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
18. 18.🔦 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 woollen thread. Does the bulb glow? (a) Yes (b) No
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 graphite rod. Does the bulb glow? (a) Yes (b) No
20. 20.Which of these means the circuit is closed? (a) the switch is OFF (b) a cell is taken out (c) a wire is cut (d) all wires are joined
21. 21.🔦 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
22. 22.🔦 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
23. 23.🔦 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
24. 24.🔦 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
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) Yes (b) No
26. 26.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
27. 27.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
28. 28.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the switch is OFF (d) the loop is complete
29. 29.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the base (c) the glass (d) the filament
30. 30.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
31. 31.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
32. 32.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
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. Does the bulb glow? (a) No (b) Yes
34. 34.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a full circuit (c) an open circuit (d) a closed circuit
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 an iron nail. Does the bulb glow? (a) Yes (b) No
36. 36.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire has come loose (c) the bulb is unscrewed (d) the switch is ON
37. 37.🔦 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
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 a steel coin. 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. 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
40. 40.🔦 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) Yes (b) No

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