Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 122 · 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 ceramic cup. Does the bulb glow? (a) No (b) Yes
2. 2.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
3. 3.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
4. 4.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
5. 5.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a full circuit (c) a series circuit (d) a closed circuit
6. 6.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
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. A gap in one wire is bridged by a rubber band. Does the bulb glow? (a) No (b) Yes
8. 8.🔦 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
9. 9.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is OFF (c) the switch is ON (d) a wire is cut
10. 10.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
11. 11.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
12. 12.🔦 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
13. 13.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire is cut (c) a wire has come loose (d) all wires are joined
14. 14.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
15. 15.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
16. 16.🔦 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
17. 17.🔁 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
18. 18.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
19. 19.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) the loop is complete (d) a wire has come loose
20. 20.🔦 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) No (b) Yes
21. 21.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the filament (d) the switch
22. 22.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
23. 23.🔦 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 glass marble. Does the bulb glow? (a) Yes (b) No
24. 24.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) it does not matter (c) only one (d) none
25. 25.🔦 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
26. 26.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the switch is OFF (d) the loop is complete
27. 27.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
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 plastic straw. Does the bulb glow? (a) No (b) Yes
29. 29.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) a wire has come loose
30. 30.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 cell is taken out
31. 31.🔦 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) Yes (b) No
32. 32.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
33. 33.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
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. Does the bulb glow? (a) Yes (b) No
35. 35.🔦 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
36. 36.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
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. A gap in one wire is bridged by a brass key. Does the bulb glow? (a) No (b) Yes
38. 38.🔦 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 copper wire. Does the bulb glow? (a) Yes (b) No
39. 39.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
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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