Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 627 · 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 copper wire. Does the bulb glow? (a) Yes (b) No
2. 2.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the base (d) the switch
3. 3.🔦 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
4. 4.🔁 What must there be for a current to flow? (a) a plastic gap (b) a broken path (c) a complete loop (d) one loose end
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) No (b) Yes
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 rubber band. Does the bulb glow? (a) No (b) Yes
7. 7.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
8. 8.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
9. 9.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
10. 10.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) a wire has come loose (d) the loop is complete
11. 11.🔦 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
12. 12.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) only one (c) it does not matter (d) both of them
13. 13.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
14. 14.Which of these means the circuit is open? (a) the bulb is unscrewed (b) all wires are joined (c) the switch is ON (d) the loop is complete
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 dry cork. Does the bulb glow? (a) Yes (b) No
16. 16.🔦 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) No (b) Yes
17. 17.🔦 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 wooden stick. Does the bulb glow? (a) No (b) Yes
18. 18.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
19. 19.🔦 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 rubber band. Does the bulb glow? (a) Yes (b) No
20. 20.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
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 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
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 ceramic cup. Does the bulb glow? (a) No (b) Yes
24. 24.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
25. 25.Which of these means the circuit is closed? (a) the switch is OFF (b) a cell is taken out (c) all wires are joined (d) a wire is cut
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 safety pin. 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 cotton thread. Does the bulb glow? (a) No (b) Yes
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 graphite rod. Does the bulb glow? (a) Yes (b) No
29. 29.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
30. 30.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
31. 31.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
32. 32.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
33. 33.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
34. 34.Which of these means the circuit is closed? (a) a wire has come loose (b) a cell is taken out (c) the switch is OFF (d) the loop is complete
35. 35.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is OFF (c) the switch is ON (d) a cell is taken out
36. 36.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
37. 37.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
38. 38.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 is cut
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 metal paper clip. 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. 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

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