Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 153 · 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. One wire has come loose from the cell. Does the bulb glow? (a) No (b) Yes
2. 2.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
3. 3.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
4. 4.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) none (c) it does not matter (d) only one
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.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a series circuit (c) a closed circuit (d) an open circuit
7. 7.🔦 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
8. 8.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
9. 9.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
10. 10.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
11. 11.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
12. 12.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the switch (c) the glass (d) the filament
13. 13.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
14. 14.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
15. 15.🔁 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
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 paper strip. Does the bulb glow? (a) Yes (b) No
17. 17.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
18. 18.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
19. 19.Which of these means the circuit is closed? (a) the switch is OFF (b) a cell is taken out (c) the switch is ON (d) a wire is cut
20. 20.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
21. 21.🔦 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
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 brass key. Does the bulb glow? (a) Yes (b) No
23. 23.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
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 glass marble. Does the bulb glow? (a) No (b) Yes
25. 25.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is OFF (c) the loop is complete (d) a wire is cut
26. 26.Which of these means the circuit is closed? (a) a wire has come loose (b) the bulb is unscrewed (c) all wires are joined (d) the switch is OFF
27. 27.🔦 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
28. 28.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
29. 29.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
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 brass key. Does the bulb glow? (a) Yes (b) No
31. 31.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
32. 32.🔦 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
33. 33.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
34. 34.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
35. 35.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
36. 36.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) the bulb is unscrewed
37. 37.Which of these means the circuit is open? (a) a wire is cut (b) the loop is complete (c) all wires are joined (d) the switch is ON
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 copper wire. Does the bulb glow? (a) No (b) Yes
39. 39.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
40. 40.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) the switch is OFF (d) all wires are joined

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