Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 296 · 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 a wire has come loose, the circuit is closed and current flows. (a) False (b) True
2. 2.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
3. 3.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
4. 4.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the switch (c) the glass (d) the filament
5. 5.Which of these means the circuit is closed? (a) all wires are joined (b) a wire has come loose (c) a wire is cut (d) the bulb is unscrewed
6. 6.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) a wire has come loose
7. 7.🔦 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) 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. A gap in one wire is bridged by a steel spoon. Does the bulb glow? (a) Yes (b) No
9. 9.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a complete loop (d) a plastic gap
10. 10.Which of these means the circuit is closed? (a) the switch is OFF (b) the switch is ON (c) a wire has come loose (d) a cell is taken out
11. 11.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
12. 12.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
13. 13.🔦 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
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 an iron nail. Does the bulb glow? (a) Yes (b) No
15. 15.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
16. 16.Which of these means the circuit is closed? (a) the loop is complete (b) the switch is OFF (c) a wire has come loose (d) a wire is cut
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 rubber eraser. Does the bulb glow? (a) Yes (b) No
18. 18.🔦 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
19. 19.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a series circuit (c) a closed circuit (d) a full circuit
20. 20.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
21. 21.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
22. 22.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
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 steel coin. Does the bulb glow? (a) No (b) Yes
24. 24.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
25. 25.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
26. 26.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
27. 27.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
28. 28.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
29. 29.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
30. 30.🔁 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) none (d) it does not matter
31. 31.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 switch is OFF
32. 32.🔦 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
33. 33.🔦 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
34. 34.🔦 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
35. 35.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
36. 36.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
37. 37.Which of these means the circuit is open? (a) all wires are joined (b) a wire is cut (c) the loop is complete (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 aluminium foil. Does the bulb glow? (a) No (b) Yes
39. 39.🔦 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 wooden stick. Does the bulb glow? (a) No (b) Yes
40. 40.Which of these means the circuit is open? (a) the loop is complete (b) the bulb is unscrewed (c) the switch is ON (d) all wires are joined

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